Perceptual precision of passive body tilt is consistent with statistically optimal cue integration

PubMed Central

Karmali, Faisal; Nicoucar, Keyvan; Merfeld, Daniel M.

2017-01-01

When making perceptual decisions, humans have been shown to optimally integrate independent noisy multisensory information, matching maximum-likelihood (ML) limits. Such ML estimators provide a theoretic limit to perceptual precision (i.e., minimal thresholds). However, how the brain combines two interacting (i.e., not independent) sensory cues remains an open question. To study the precision achieved when combining interacting sensory signals, we measured perceptual roll tilt and roll rotation thresholds between 0 and 5 Hz in six normal human subjects. Primary results show that roll tilt thresholds between 0.2 and 0.5 Hz were significantly lower than predicted by a ML estimator that includes only vestibular contributions that do not interact. In this paper, we show how other cues (e.g., somatosensation) and an internal representation of sensory and body dynamics might independently contribute to the observed performance enhancement. In short, a Kalman filter was combined with an ML estimator to match human performance, whereas the potential contribution of nonvestibular cues was assessed using published bilateral loss patient data. Our results show that a Kalman filter model including previously proven canal-otolith interactions alone (without nonvestibular cues) can explain the observed performance enhancements as can a model that includes nonvestibular contributions. NEW & NOTEWORTHY We found that human whole body self-motion direction-recognition thresholds measured during dynamic roll tilts were significantly lower than those predicted by a conventional maximum-likelihood weighting of the roll angular velocity and quasistatic roll tilt cues. Here, we show that two models can each match this “apparent” better-than-optimal performance: 1) inclusion of a somatosensory contribution and 2) inclusion of a dynamic sensory interaction between canal and otolith cues via a Kalman filter model. PMID:28179477

Robust cue integration: a Bayesian model and evidence from cue-conflict studies with stereoscopic and figure cues to slant.

PubMed

Knill, David C

2007-05-23

Most research on depth cue integration has focused on stimulus regimes in which stimuli contain the small cue conflicts that one might expect to normally arise from sensory noise. In these regimes, linear models for cue integration provide a good approximation to system performance. This article focuses on situations in which large cue conflicts can naturally occur in stimuli. We describe a Bayesian model for nonlinear cue integration that makes rational inferences about scenes across the entire range of possible cue conflicts. The model derives from the simple intuition that multiple properties of scenes or causal factors give rise to the image information associated with most cues. To make perceptual inferences about one property of a scene, an ideal observer must necessarily take into account the possible contribution of these other factors to the information provided by a cue. In the context of classical depth cues, large cue conflicts most commonly arise when one or another cue is generated by an object or scene that violates the strongest form of constraint that makes the cue informative. For example, when binocularly viewing a slanted trapezoid, the slant interpretation of the figure derived by assuming that the figure is rectangular may conflict greatly with the slant suggested by stereoscopic disparities. An optimal Bayesian estimator incorporates the possibility that different constraints might apply to objects in the world and robustly integrates cues with large conflicts by effectively switching between different internal models of the prior constraints underlying one or both cues. We performed two experiments to test the predictions of the model when applied to estimating surface slant from binocular disparities and the compression cue (the aspect ratio of figures in an image). The apparent weight that subjects gave to the compression cue decreased smoothly as a function of the conflict between the cues but did not shrink to zero; that is, subjects did not fully veto the compression cue at large cue conflicts. A Bayesian model that assumes a mixed prior distribution of figure shapes in the world, with a large proportion being very regular and a smaller proportion having random shapes, provides a good quantitative fit for subjects' performance. The best fitting model parameters are consistent with the sensory noise to be expected in measurements of figure shape, further supporting the Bayesian model as an account of robust cue integration.

Sequential Modelling of Building Rooftops by Integrating Airborne LIDAR Data and Optical Imagery: Preliminary Results

NASA Astrophysics Data System (ADS)

Sohn, G.; Jung, J.; Jwa, Y.; Armenakis, C.

2013-05-01

This paper presents a sequential rooftop modelling method to refine initial rooftop models derived from airborne LiDAR data by integrating it with linear cues retrieved from single imagery. A cue integration between two datasets is facilitated by creating new topological features connecting between the initial model and image lines, with which new model hypotheses (variances to the initial model) are produced. We adopt Minimum Description Length (MDL) principle for competing the model candidates and selecting the optimal model by considering the balanced trade-off between the model closeness and the model complexity. Our preliminary results, combined with the Vaihingen data provided by ISPRS WGIII/4 demonstrate the image-driven modelling cues can compensate the limitations posed by LiDAR data in rooftop modelling.

Audiovisual integration increases the intentional step synchronization of side-by-side walkers.

PubMed

Noy, Dominic; Mouta, Sandra; Lamas, Joao; Basso, Daniel; Silva, Carlos; Santos, Jorge A

2017-12-01

When people walk side-by-side, they often synchronize their steps. To achieve this, individuals might cross-modally match audiovisual signals from the movements of the partner and kinesthetic, cutaneous, visual and auditory signals from their own movements. Because signals from different sensory systems are processed with noise and asynchronously, the challenge of the CNS is to derive the best estimate based on this conflicting information. This is currently thought to be done by a mechanism operating as a Maximum Likelihood Estimator (MLE). The present work investigated whether audiovisual signals from the partner are integrated according to MLE in order to synchronize steps during walking. Three experiments were conducted in which the sensory cues from a walking partner were virtually simulated. In Experiment 1 seven participants were instructed to synchronize with human-sized Point Light Walkers and/or footstep sounds. Results revealed highest synchronization performance with auditory and audiovisual cues. This was quantified by the time to achieve synchronization and by synchronization variability. However, this auditory dominance effect might have been due to artifacts of the setup. Therefore, in Experiment 2 human-sized virtual mannequins were implemented. Also, audiovisual stimuli were rendered in real-time and thus were synchronous and co-localized. All four participants synchronized best with audiovisual cues. For three of the four participants results point toward their optimal integration consistent with the MLE model. Experiment 3 yielded performance decrements for all three participants when the cues were incongruent. Overall, these findings suggest that individuals might optimally integrate audiovisual cues to synchronize steps during side-by-side walking. Copyright © 2017 Elsevier B.V. All rights reserved.

Late development of cue integration is linked to sensory fusion in cortex.

PubMed

Dekker, Tessa M; Ban, Hiroshi; van der Velde, Bauke; Sereno, Martin I; Welchman, Andrew E; Nardini, Marko

2015-11-02

Adults optimize perceptual judgements by integrating different types of sensory information [1, 2]. This engages specialized neural circuits that fuse signals from the same [3-5] or different [6] modalities. Whereas young children can use sensory cues independently, adult-like precision gains from cue combination only emerge around ages 10 to 11 years [7-9]. Why does it take so long to make best use of sensory information? Existing data cannot distinguish whether this (1) reflects surprisingly late changes in sensory processing (sensory integration mechanisms in the brain are still developing) or (2) depends on post-perceptual changes (integration in sensory cortex is adult-like, but higher-level decision processes do not access the information) [10]. We tested visual depth cue integration in the developing brain to distinguish these possibilities. We presented children aged 6-12 years with displays depicting depth from binocular disparity and relative motion and made measurements using psychophysics, retinotopic mapping, and pattern classification fMRI. Older children (>10.5 years) showed clear evidence for sensory fusion in V3B, a visual area thought to integrate depth cues in the adult brain [3-5]. By contrast, in younger children (<10.5 years), there was no evidence for sensory fusion in any visual area. This significant age difference was paired with a shift in perceptual performance around ages 10 to 11 years and could not be explained by motion artifacts, visual attention, or signal quality differences. Thus, whereas many basic visual processes mature early in childhood [11, 12], the brain circuits that fuse cues take a very long time to develop. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Late Development of Cue Integration Is Linked to Sensory Fusion in Cortex

PubMed Central

Dekker, Tessa M.; Ban, Hiroshi; van der Velde, Bauke; Sereno, Martin I.; Welchman, Andrew E.; Nardini, Marko

2015-01-01

Summary Adults optimize perceptual judgements by integrating different types of sensory information [1, 2]. This engages specialized neural circuits that fuse signals from the same [3, 4, 5] or different [6] modalities. Whereas young children can use sensory cues independently, adult-like precision gains from cue combination only emerge around ages 10 to 11 years [7, 8, 9]. Why does it take so long to make best use of sensory information? Existing data cannot distinguish whether this (1) reflects surprisingly late changes in sensory processing (sensory integration mechanisms in the brain are still developing) or (2) depends on post-perceptual changes (integration in sensory cortex is adult-like, but higher-level decision processes do not access the information) [10]. We tested visual depth cue integration in the developing brain to distinguish these possibilities. We presented children aged 6–12 years with displays depicting depth from binocular disparity and relative motion and made measurements using psychophysics, retinotopic mapping, and pattern classification fMRI. Older children (>10.5 years) showed clear evidence for sensory fusion in V3B, a visual area thought to integrate depth cues in the adult brain [3, 4, 5]. By contrast, in younger children (<10.5 years), there was no evidence for sensory fusion in any visual area. This significant age difference was paired with a shift in perceptual performance around ages 10 to 11 years and could not be explained by motion artifacts, visual attention, or signal quality differences. Thus, whereas many basic visual processes mature early in childhood [11, 12], the brain circuits that fuse cues take a very long time to develop. PMID:26480841

Integration trumps selection in object recognition.

PubMed

Saarela, Toni P; Landy, Michael S

2015-03-30

Finding and recognizing objects is a fundamental task of vision. Objects can be defined by several "cues" (color, luminance, texture, etc.), and humans can integrate sensory cues to improve detection and recognition [1-3]. Cortical mechanisms fuse information from multiple cues [4], and shape-selective neural mechanisms can display cue invariance by responding to a given shape independent of the visual cue defining it [5-8]. Selective attention, in contrast, improves recognition by isolating a subset of the visual information [9]. Humans can select single features (red or vertical) within a perceptual dimension (color or orientation), giving faster and more accurate responses to items having the attended feature [10, 11]. Attention elevates neural responses and sharpens neural tuning to the attended feature, as shown by studies in psychophysics and modeling [11, 12], imaging [13-16], and single-cell and neural population recordings [17, 18]. Besides single features, attention can select whole objects [19-21]. Objects are among the suggested "units" of attention because attention to a single feature of an object causes the selection of all of its features [19-21]. Here, we pit integration against attentional selection in object recognition. We find, first, that humans can integrate information near optimally from several perceptual dimensions (color, texture, luminance) to improve recognition. They cannot, however, isolate a single dimension even when the other dimensions provide task-irrelevant, potentially conflicting information. For object recognition, it appears that there is mandatory integration of information from multiple dimensions of visual experience. The advantage afforded by this integration, however, comes at the expense of attentional selection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Salient object detection based on discriminative boundary and multiple cues integration

NASA Astrophysics Data System (ADS)

Jiang, Qingzhu; Wu, Zemin; Tian, Chang; Liu, Tao; Zeng, Mingyong; Hu, Lei

2016-01-01

In recent years, many saliency models have achieved good performance by taking the image boundary as the background prior. However, if all boundaries of an image are equally and artificially selected as background, misjudgment may happen when the object touches the boundary. We propose an algorithm called weighted contrast optimization based on discriminative boundary (wCODB). First, a background estimation model is reliably constructed through discriminating each boundary via Hausdorff distance. Second, the background-only weighted contrast is improved by fore-background weighted contrast, which is optimized through weight-adjustable optimization framework. Then to objectively estimate the quality of a saliency map, a simple but effective metric called spatial distribution of saliency map and mean saliency in covered window ratio (MSR) is designed. Finally, in order to further promote the detection result using MSR as the weight, we propose a saliency fusion framework to integrate three other cues-uniqueness, distribution, and coherence from three representative methods into our wCODB model. Extensive experiments on six public datasets demonstrate that our wCODB performs favorably against most of the methods based on boundary, and the integrated result outperforms all state-of-the-art methods.

Reliability and relative weighting of visual and nonvisual information for perceiving direction of self-motion during walking

PubMed Central

Saunders, Jeffrey A.

2014-01-01

Direction of self-motion during walking is indicated by multiple cues, including optic flow, nonvisual sensory cues, and motor prediction. I measured the reliability of perceived heading from visual and nonvisual cues during walking, and whether cues are weighted in an optimal manner. I used a heading alignment task to measure perceived heading during walking. Observers walked toward a target in a virtual environment with and without global optic flow. The target was simulated to be infinitely far away, so that it did not provide direct feedback about direction of self-motion. Variability in heading direction was low even without optic flow, with average RMS error of 2.4°. Global optic flow reduced variability to 1.9°–2.1°, depending on the structure of the environment. The small amount of variance reduction was consistent with optimal use of visual information. The relative contribution of visual and nonvisual information was also measured using cue conflict conditions. Optic flow specified a conflicting heading direction (±5°), and bias in walking direction was used to infer relative weighting. Visual feedback influenced heading direction by 16%–34% depending on scene structure, with more effect with dense motion parallax. The weighting of visual feedback was close to the predictions of an optimal integration model given the observed variability measures. PMID:24648194

Cue-based assertion classification for Swedish clinical text – developing a lexicon for pyConTextSwe

PubMed Central

Velupillai, Sumithra; Skeppstedt, Maria; Kvist, Maria; Mowery, Danielle; Chapman, Brian E.; Dalianis, Hercules; Chapman, Wendy W.

2014-01-01

Objective The ability of a cue-based system to accurately assert whether a disorder is affirmed, negated, or uncertain is dependent, in part, on its cue lexicon. In this paper, we continue our study of porting an assertion system (pyConTextNLP) from English to Swedish (pyConTextSwe) by creating an optimized assertion lexicon for clinical Swedish. Methods and material We integrated cues from four external lexicons, along with generated inflections and combinations. We used subsets of a clinical corpus in Swedish. We applied four assertion classes (definite existence, probable existence, probable negated existence and definite negated existence) and two binary classes (existence yes/no and uncertainty yes/no) to pyConTextSwe. We compared pyConTextSwe’s performance with and without the added cues on a development set, and improved the lexicon further after an error analysis. On a separate evaluation set, we calculated the system’s final performance. Results Following integration steps, we added 454 cues to pyConTextSwe. The optimized lexicon developed after an error analysis resulted in statistically significant improvements on the development set (83% F-score, overall). The system’s final F-scores on an evaluation set were 81% (overall). For the individual assertion classes, F-score results were 88% (definite existence), 81% (probable existence), 55% (probable negated existence), and 63% (definite negated existence). For the binary classifications existence yes/no and uncertainty yes/no, final system performance was 97%/87% and 78%/86% F-score, respectively. Conclusions We have successfully ported pyConTextNLP to Swedish (pyConTextSwe). We have created an extensive and useful assertion lexicon for Swedish clinical text, which could form a valuable resource for similar studies, and which is publicly available. PMID:24556644

Probabilistic inference under time pressure leads to a cortical-to-subcortical shift in decision evidence integration.

PubMed

Oh-Descher, Hanna; Beck, Jeffrey M; Ferrari, Silvia; Sommer, Marc A; Egner, Tobias

2017-11-15

Real-life decision-making often involves combining multiple probabilistic sources of information under finite time and cognitive resources. To mitigate these pressures, people "satisfice", foregoing a full evaluation of all available evidence to focus on a subset of cues that allow for fast and "good-enough" decisions. Although this form of decision-making likely mediates many of our everyday choices, very little is known about the way in which the neural encoding of cue information changes when we satisfice under time pressure. Here, we combined human functional magnetic resonance imaging (fMRI) with a probabilistic classification task to characterize neural substrates of multi-cue decision-making under low (1500 ms) and high (500 ms) time pressure. Using variational Bayesian inference, we analyzed participants' choices to track and quantify cue usage under each experimental condition, which was then applied to model the fMRI data. Under low time pressure, participants performed near-optimally, appropriately integrating all available cues to guide choices. Both cortical (prefrontal and parietal cortex) and subcortical (hippocampal and striatal) regions encoded individual cue weights, and activity linearly tracked trial-by-trial variations in the amount of evidence and decision uncertainty. Under increased time pressure, participants adaptively shifted to using a satisficing strategy by discounting the least informative cue in their decision process. This strategic change in decision-making was associated with an increased involvement of the dopaminergic midbrain, striatum, thalamus, and cerebellum in representing and integrating cue values. We conclude that satisficing the probabilistic inference process under time pressure leads to a cortical-to-subcortical shift in the neural drivers of decisions. Copyright © 2017 Elsevier Inc. All rights reserved.

Learning Multisensory Integration and Coordinate Transformation via Density Estimation

PubMed Central

Sabes, Philip N.

2013-01-01

Sensory processing in the brain includes three key operations: multisensory integration—the task of combining cues into a single estimate of a common underlying stimulus; coordinate transformations—the change of reference frame for a stimulus (e.g., retinotopic to body-centered) effected through knowledge about an intervening variable (e.g., gaze position); and the incorporation of prior information. Statistically optimal sensory processing requires that each of these operations maintains the correct posterior distribution over the stimulus. Elements of this optimality have been demonstrated in many behavioral contexts in humans and other animals, suggesting that the neural computations are indeed optimal. That the relationships between sensory modalities are complex and plastic further suggests that these computations are learned—but how? We provide a principled answer, by treating the acquisition of these mappings as a case of density estimation, a well-studied problem in machine learning and statistics, in which the distribution of observed data is modeled in terms of a set of fixed parameters and a set of latent variables. In our case, the observed data are unisensory-population activities, the fixed parameters are synaptic connections, and the latent variables are multisensory-population activities. In particular, we train a restricted Boltzmann machine with the biologically plausible contrastive-divergence rule to learn a range of neural computations not previously demonstrated under a single approach: optimal integration; encoding of priors; hierarchical integration of cues; learning when not to integrate; and coordinate transformation. The model makes testable predictions about the nature of multisensory representations. PMID:23637588

Texture and haptic cues in slant discrimination: reliability-based cue weighting without statistically optimal cue combination

NASA Astrophysics Data System (ADS)

Rosas, Pedro; Wagemans, Johan; Ernst, Marc O.; Wichmann, Felix A.

2005-05-01

A number of models of depth-cue combination suggest that the final depth percept results from a weighted average of independent depth estimates based on the different cues available. The weight of each cue in such an average is thought to depend on the reliability of each cue. In principle, such a depth estimation could be statistically optimal in the sense of producing the minimum-variance unbiased estimator that can be constructed from the available information. Here we test such models by using visual and haptic depth information. Different texture types produce differences in slant-discrimination performance, thus providing a means for testing a reliability-sensitive cue-combination model with texture as one of the cues to slant. Our results show that the weights for the cues were generally sensitive to their reliability but fell short of statistically optimal combination - we find reliability-based reweighting but not statistically optimal cue combination.

Integration trumps selection in object recognition

PubMed Central

Saarela, Toni P.; Landy, Michael S.

2015-01-01

Summary Finding and recognizing objects is a fundamental task of vision. Objects can be defined by several “cues” (color, luminance, texture etc.), and humans can integrate sensory cues to improve detection and recognition [1–3]. Cortical mechanisms fuse information from multiple cues [4], and shape-selective neural mechanisms can display cue-invariance by responding to a given shape independent of the visual cue defining it [5–8]. Selective attention, in contrast, improves recognition by isolating a subset of the visual information [9]. Humans can select single features (red or vertical) within a perceptual dimension (color or orientation), giving faster and more accurate responses to items having the attended feature [10,11]. Attention elevates neural responses and sharpens neural tuning to the attended feature, as shown by studies in psychophysics and modeling [11,12], imaging [13–16], and single-cell and neural population recordings [17,18]. Besides single features, attention can select whole objects [19–21]. Objects are among the suggested “units” of attention because attention to a single feature of an object causes the selection of all of its features [19–21]. Here, we pit integration against attentional selection in object recognition. We find, first, that humans can integrate information near-optimally from several perceptual dimensions (color, texture, luminance) to improve recognition. They cannot, however, isolate a single dimension even when the other dimensions provide task-irrelevant, potentially conflicting information. For object recognition, it appears that there is mandatory integration of information from multiple dimensions of visual experience. The advantage afforded by this integration, however, comes at the expense of attentional selection. PMID:25802154

Inclusion of Specialist and Generalist Stimuli in Attract-and-Kill Programs: Their Relative Efficacy in Apple Maggot Fly (Diptera: Tephritidae) Pest Management.

PubMed

Morrison, William R; Lee, Doo-Hyung; Reissig, W Harvey; Combs, David; Leahy, Kathleen; Tuttle, Arthur; Cooley, Daniel; Leskey, Tracy C

2016-08-01

Investigating the chemical ecology of agricultural systems continues to be a salient part of integrated pest management programs. Apple maggot fly, a key pest of apple in eastern North America, is a visual specialist with attraction to host fruit-mimicking cues. These cues have been incorporated into red spherical traps used for both monitoring and behaviorally based management. Incorporating generalist or specialist olfactory cues can potentially increase the overall success of this management system. The primary aim of this study was to evaluate the attractiveness of a generalist olfactory cue, ammonium carbonate, and the specialist olfactory cue, a five-component apple volatile blend, when included as a component of a red attracticidal sphere system. Secondly, we assessed how critical it was to maintain minimal deviation from the optimal, full-round specialist visual stimulus provided by red spheres. Finally, attracticidal spheres were deployed with specialist olfactory cues in commercial apple orchards to evaluate their potential for effective management of apple maggot. Ammonium carbonate did not increase residency, feeding time, or mortality in the laboratory-based trials. Field deployment of specialist olfactory cues increased apple maggot captures on red spheres, while the generalist cue did not. Apple maggot tolerated some deviation from the optimal visual stimulus without reducing captures on red spheres. Attracticidal spheres hung in perimeter trees in orchards resulted in acceptable and statistically identical levels of control compared with standard insecticide programs used by growers. Overall, our study contributes valuable information for developing a reliable attract-and-kill system for apple maggot. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the United States.

Spatial reference frames of visual, vestibular, and multimodal heading signals in the dorsal subdivision of the medial superior temporal area.

PubMed

Fetsch, Christopher R; Wang, Sentao; Gu, Yong; Deangelis, Gregory C; Angelaki, Dora E

2007-01-17

Heading perception is a complex task that generally requires the integration of visual and vestibular cues. This sensory integration is complicated by the fact that these two modalities encode motion in distinct spatial reference frames (visual, eye-centered; vestibular, head-centered). Visual and vestibular heading signals converge in the primate dorsal subdivision of the medial superior temporal area (MSTd), a region thought to contribute to heading perception, but the reference frames of these signals remain unknown. We measured the heading tuning of MSTd neurons by presenting optic flow (visual condition), inertial motion (vestibular condition), or a congruent combination of both cues (combined condition). Static eye position was varied from trial to trial to determine the reference frame of tuning (eye-centered, head-centered, or intermediate). We found that tuning for optic flow was predominantly eye-centered, whereas tuning for inertial motion was intermediate but closer to head-centered. Reference frames in the two unimodal conditions were rarely matched in single neurons and uncorrelated across the population. Notably, reference frames in the combined condition varied as a function of the relative strength and spatial congruency of visual and vestibular tuning. This represents the first investigation of spatial reference frames in a naturalistic, multimodal condition in which cues may be integrated to improve perceptual performance. Our results compare favorably with the predictions of a recent neural network model that uses a recurrent architecture to perform optimal cue integration, suggesting that the brain could use a similar computational strategy to integrate sensory signals expressed in distinct frames of reference.

What aspects of vision facilitate haptic processing?

PubMed

Millar, Susanna; Al-Attar, Zainab

2005-12-01

We investigate how vision affects haptic performance when task-relevant visual cues are reduced or excluded. The task was to remember the spatial location of six landmarks that were explored by touch in a tactile map. Here, we use specially designed spectacles that simulate residual peripheral vision, tunnel vision, diffuse light perception, and total blindness. Results for target locations differed, suggesting additional effects from adjacent touch cues. These are discussed. Touch with full vision was most accurate, as expected. Peripheral and tunnel vision, which reduce visuo-spatial cues, differed in error pattern. Both were less accurate than full vision, and significantly more accurate than touch with diffuse light perception, and touch alone. The important finding was that touch with diffuse light perception, which excludes spatial cues, did not differ from touch without vision in performance accuracy, nor in location error pattern. The contrast between spatially relevant versus spatially irrelevant vision provides new, rather decisive, evidence against the hypothesis that vision affects haptic processing even if it does not add task-relevant information. The results support optimal integration theories, and suggest that spatial and non-spatial aspects of vision need explicit distinction in bimodal studies and theories of spatial integration.

Objective Fidelity Evaluation in Multisensory Virtual Environments: Auditory Cue Fidelity in Flight Simulation

PubMed Central

Meyer, Georg F.; Wong, Li Ting; Timson, Emma; Perfect, Philip; White, Mark D.

2012-01-01

We argue that objective fidelity evaluation of virtual environments, such as flight simulation, should be human-performance-centred and task-specific rather than measure the match between simulation and physical reality. We show how principled experimental paradigms and behavioural models to quantify human performance in simulated environments that have emerged from research in multisensory perception provide a framework for the objective evaluation of the contribution of individual cues to human performance measures of fidelity. We present three examples in a flight simulation environment as a case study: Experiment 1: Detection and categorisation of auditory and kinematic motion cues; Experiment 2: Performance evaluation in a target-tracking task; Experiment 3: Transferrable learning of auditory motion cues. We show how the contribution of individual cues to human performance can be robustly evaluated for each task and that the contribution is highly task dependent. The same auditory cues that can be discriminated and are optimally integrated in experiment 1, do not contribute to target-tracking performance in an in-flight refuelling simulation without training, experiment 2. In experiment 3, however, we demonstrate that the auditory cue leads to significant, transferrable, performance improvements with training. We conclude that objective fidelity evaluation requires a task-specific analysis of the contribution of individual cues. PMID:22957068

Attentional and Contextual Priors in Sound Perception.

PubMed

Wolmetz, Michael; Elhilali, Mounya

2016-01-01

Behavioral and neural studies of selective attention have consistently demonstrated that explicit attentional cues to particular perceptual features profoundly alter perception and performance. The statistics of the sensory environment can also provide cues about what perceptual features to expect, but the extent to which these more implicit contextual cues impact perception and performance, as well as their relationship to explicit attentional cues, is not well understood. In this study, the explicit cues, or attentional prior probabilities, and the implicit cues, or contextual prior probabilities, associated with different acoustic frequencies in a detection task were simultaneously manipulated. Both attentional and contextual priors had similarly large but independent impacts on sound detectability, with evidence that listeners tracked and used contextual priors for a variety of sound classes (pure tones, harmonic complexes, and vowels). Further analyses showed that listeners updated their contextual priors rapidly and optimally, given the changing acoustic frequency statistics inherent in the paradigm. A Bayesian Observer model accounted for both attentional and contextual adaptations found with listeners. These results bolster the interpretation of perception as Bayesian inference, and suggest that some effects attributed to selective attention may be a special case of contextual prior integration along a feature axis.

Attentional and Contextual Priors in Sound Perception

PubMed Central

Wolmetz, Michael; Elhilali, Mounya

2016-01-01

Behavioral and neural studies of selective attention have consistently demonstrated that explicit attentional cues to particular perceptual features profoundly alter perception and performance. The statistics of the sensory environment can also provide cues about what perceptual features to expect, but the extent to which these more implicit contextual cues impact perception and performance, as well as their relationship to explicit attentional cues, is not well understood. In this study, the explicit cues, or attentional prior probabilities, and the implicit cues, or contextual prior probabilities, associated with different acoustic frequencies in a detection task were simultaneously manipulated. Both attentional and contextual priors had similarly large but independent impacts on sound detectability, with evidence that listeners tracked and used contextual priors for a variety of sound classes (pure tones, harmonic complexes, and vowels). Further analyses showed that listeners updated their contextual priors rapidly and optimally, given the changing acoustic frequency statistics inherent in the paradigm. A Bayesian Observer model accounted for both attentional and contextual adaptations found with listeners. These results bolster the interpretation of perception as Bayesian inference, and suggest that some effects attributed to selective attention may be a special case of contextual prior integration along a feature axis. PMID:26882228

An optimality framework to predict decomposer carbon-use efficiency trends along stoichiometric gradients

NASA Astrophysics Data System (ADS)

Manzoni, S.; Capek, P.; Mooshammer, M.; Lindahl, B.; Richter, A.; Santruckova, H.

2016-12-01

Litter and soil organic matter decomposers feed on substrates with much wider C:N and C:P ratios then their own cellular composition, raising the question as to how they can adapt their metabolism to such a chronic stoichiometric imbalance. Here we propose an optimality framework to address this question, based on the hypothesis that carbon-use efficiency (CUE) can be optimally adjusted to maximize the decomposer growth rate. When nutrients are abundant, increasing CUE improves decomposer growth rate, at the expense of higher nutrient demand. However, when nutrients are scarce, increased nutrient demand driven by high CUE can trigger nutrient limitation and inhibit growth. An intermediate, `optimal' CUE ensures balanced growth at the verge of nutrient limitation. We derive a simple analytical equation that links this optimal CUE to organic substrate and decomposer biomass C:N and C:P ratios, and to the rate of inorganic nutrient supply (e.g., fertilization). This equation allows formulating two specific hypotheses: i) decomposer CUE should increase with widening organic substrate C:N and C:P ratios with a scaling exponent between 0 (with abundant inorganic nutrients) and -1 (scarce inorganic nutrients), and ii) CUE should increase with increasing inorganic nutrient supply, for a given organic substrate stoichiometry. These hypotheses are tested using a new database encompassing nearly 2000 estimates of CUE from about 160 studies, spanning aquatic and terrestrial decomposers of litter and more stabilized organic matter. The theoretical predictions are largely confirmed by our data analysis, except for the lack of fertilization effects on terrestrial decomposer CUE. While stoichiometric drivers constrain the general trends in CUE, the relatively large variability in CUE estimates suggests that other factors could be at play as well. For example, temperature is often cited as a potential driver of CUE, but we only found limited evidence of temperature effects, although in some subsets of data, temperature and substrate stoichiometry appeared to interact. Based on our results, the optimality principle can provide a solid (but still incomplete) framework to develop CUE models for large-scale applications.

Sensorimotor Adaptations Following Exposure to Ambiguous Inertial Motion Cues

NASA Technical Reports Server (NTRS)

Wood, S. J.; Harm, D. L.; Reschke, M. F.; Rupert, A. H.; Clement, G. R.

2009-01-01

The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. We hypothesize that multi-sensory integration will be adaptively optimized in altered gravity environments based on the dynamics of other sensory information available, with greater changes in otolith-mediated responses in the mid-frequency range where there is a crossover of tilt and translation responses. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of tilt-translation disturbances during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation.

Satisficing in split-second decision making is characterized by strategic cue discounting.

PubMed

Oh, Hanna; Beck, Jeffrey M; Zhu, Pingping; Sommer, Marc A; Ferrari, Silvia; Egner, Tobias

2016-12-01

Much of our real-life decision making is bounded by uncertain information, limitations in cognitive resources, and a lack of time to allocate to the decision process. It is thought that humans overcome these limitations through satisficing, fast but "good-enough" heuristic decision making that prioritizes some sources of information (cues) while ignoring others. However, the decision-making strategies we adopt under uncertainty and time pressure, for example during emergencies that demand split-second choices, are presently unknown. To characterize these decision strategies quantitatively, the present study examined how people solve a novel multicue probabilistic classification task under varying time pressure, by tracking shifts in decision strategies using variational Bayesian inference. We found that under low time pressure, participants correctly weighted and integrated all available cues to arrive at near-optimal decisions. With increasingly demanding, subsecond time pressures, however, participants systematically discounted a subset of the cue information by dropping the least informative cue(s) from their decision making process. Thus, the human cognitive apparatus copes with uncertainty and severe time pressure by adopting a "drop-the-worst" cue decision making strategy that minimizes cognitive time and effort investment while preserving the consideration of the most diagnostic cue information, thus maintaining "good-enough" accuracy. This advance in our understanding of satisficing strategies could form the basis of predicting human choices in high time pressure scenarios. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Computational models of the Posner simple and choice reaction time tasks

PubMed Central

Feher da Silva, Carolina; Baldo, Marcus V. C.

2015-01-01

The landmark experiments by Posner in the late 1970s have shown that reaction time (RT) is faster when the stimulus appears in an expected location, as indicated by a cue; since then, the so-called Posner task has been considered a “gold standard” test of spatial attention. It is thus fundamental to understand the neural mechanisms involved in performing it. To this end, we have developed a Bayesian detection system and small integrate-and-fire neural networks, which modeled sensory and motor circuits, respectively, and optimized them to perform the Posner task under different cue type proportions and noise levels. In doing so, main findings of experimental research on RT were replicated: the relative frequency effect, suboptimal RTs and significant error rates due to noise and invalid cues, slower RT for choice RT tasks than for simple RT tasks, fastest RTs for valid cues and slowest RTs for invalid cues. Analysis of the optimized systems revealed that the employed mechanisms were consistent with related findings in neurophysiology. Our models predict that (1) the results of a Posner task may be affected by the relative frequency of valid and neutral trials, (2) in simple RT tasks, input from multiple locations are added together to compose a stronger signal, and (3) the cue affects motor circuits more strongly in choice RT tasks than in simple RT tasks. In discussing the computational demands of the Posner task, attention has often been described as a filter that protects the nervous system, whose capacity is limited, from information overload. Our models, however, reveal that the main problems that must be overcome to perform the Posner task effectively are distinguishing signal from external noise and selecting the appropriate response in the presence of internal noise. PMID:26190997

Can You Hear That Peak? Utilization of Auditory and Visual Feedback at Peak Limb Velocity

ERIC Educational Resources Information Center

Loria, Tristan; de Grosbois, John; Tremblay, Luc

2016-01-01

Purpose: At rest, the central nervous system combines and integrates multisensory cues to yield an optimal percept. When engaging in action, the relative weighing of sensory modalities has been shown to be altered. Because the timing of peak velocity is the critical moment in some goal-directed movements (e.g., overarm throwing), the current study…

Bayesian Integration of Information in Hippocampal Place Cells

PubMed Central

Madl, Tamas; Franklin, Stan; Chen, Ke; Montaldi, Daniela; Trappl, Robert

2014-01-01

Accurate spatial localization requires a mechanism that corrects for errors, which might arise from inaccurate sensory information or neuronal noise. In this paper, we propose that Hippocampal place cells might implement such an error correction mechanism by integrating different sources of information in an approximately Bayes-optimal fashion. We compare the predictions of our model with physiological data from rats. Our results suggest that useful predictions regarding the firing fields of place cells can be made based on a single underlying principle, Bayesian cue integration, and that such predictions are possible using a remarkably small number of model parameters. PMID:24603429

System-level modeling of acetone-butanol-ethanol fermentation.

PubMed

Liao, Chen; Seo, Seung-Oh; Lu, Ting

2016-05-01

Acetone-butanol-ethanol (ABE) fermentation is a metabolic process of clostridia that produces bio-based solvents including butanol. It is enabled by an underlying metabolic reaction network and modulated by cellular gene regulation and environmental cues. Mathematical modeling has served as a valuable strategy to facilitate the understanding, characterization and optimization of this process. In this review, we highlight recent advances in system-level, quantitative modeling of ABE fermentation. We begin with an overview of integrative processes underlying the fermentation. Next we survey modeling efforts including early simple models, models with a systematic metabolic description, and those incorporating metabolism through simple gene regulation. Particular focus is given to a recent system-level model that integrates the metabolic reactions, gene regulation and environmental cues. We conclude by discussing the remaining challenges and future directions towards predictive understanding of ABE fermentation. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Nonlinear Motion Cueing Algorithm: Filtering at Pilot Station and Development of the Nonlinear Optimal Filters for Pitch and Roll

NASA Technical Reports Server (NTRS)

Zaychik, Kirill B.; Cardullo, Frank M.

2012-01-01

Telban and Cardullo have developed and successfully implemented the non-linear optimal motion cueing algorithm at the Visual Motion Simulator (VMS) at the NASA Langley Research Center in 2005. The latest version of the non-linear algorithm performed filtering of motion cues in all degrees-of-freedom except for pitch and roll. This manuscript describes the development and implementation of the non-linear optimal motion cueing algorithm for the pitch and roll degrees of freedom. Presented results indicate improved cues in the specified channels as compared to the original design. To further advance motion cueing in general, this manuscript describes modifications to the existing algorithm, which allow for filtering at the location of the pilot's head as opposed to the centroid of the motion platform. The rational for such modification to the cueing algorithms is that the location of the pilot's vestibular system must be taken into account as opposed to the off-set of the centroid of the cockpit relative to the center of rotation alone. Results provided in this report suggest improved performance of the motion cueing algorithm.

Speech Cues Contribute to Audiovisual Spatial Integration

PubMed Central

Bishop, Christopher W.; Miller, Lee M.

2011-01-01

Speech is the most important form of human communication but ambient sounds and competing talkers often degrade its acoustics. Fortunately the brain can use visual information, especially its highly precise spatial information, to improve speech comprehension in noisy environments. Previous studies have demonstrated that audiovisual integration depends strongly on spatiotemporal factors. However, some integrative phenomena such as McGurk interference persist even with gross spatial disparities, suggesting that spatial alignment is not necessary for robust integration of audiovisual place-of-articulation cues. It is therefore unclear how speech-cues interact with audiovisual spatial integration mechanisms. Here, we combine two well established psychophysical phenomena, the McGurk effect and the ventriloquist's illusion, to explore this dependency. Our results demonstrate that conflicting spatial cues may not interfere with audiovisual integration of speech, but conflicting speech-cues can impede integration in space. This suggests a direct but asymmetrical influence between ventral ‘what’ and dorsal ‘where’ pathways. PMID:21909378

Pitch contour identification with combined place and temporal cues using cochlear implants

PubMed Central

Luo, Xin; Padilla, Monica; Landsberger, David M.

2012-01-01

This study investigated the integration of place- and temporal-pitch cues in pitch contour identification (PCI), in which cochlear implant (CI) users were asked to judge the overall pitch-change direction of stimuli. Falling and rising pitch contours were created either by continuously steering current between adjacent electrodes (place pitch), by continuously changing amplitude modulation (AM) frequency (temporal pitch), or both. The percentage of rising responses was recorded as a function of current steering or AM frequency change, with single or combined pitch cues. A significant correlation was found between subjects’ sensitivity to current steering and AM frequency change. The integration of place- and temporal-pitch cues was most effective when the two cues were similarly discriminable in isolation. Adding the other (place or temporal) pitch cues shifted the temporal- or place-pitch psychometric functions horizontally without changing the slopes. PCI was significantly better with consistent place- and temporal-pitch cues than with inconsistent cues. PCI with single cues and integration of pitch cues were similar on different electrodes. The results suggest that CI users effectively integrate place- and temporal-pitch cues in relative pitch perception tasks. Current steering and AM frequency change should be coordinated to better transmit dynamic pitch information to CI users. PMID:22352506

Efficiency of extracting stereo-driven object motions

PubMed Central

Jain, Anshul; Zaidi, Qasim

2013-01-01

Most living things and many nonliving things deform as they move, requiring observers to separate object motions from object deformations. When the object is partially occluded, the task becomes more difficult because it is not possible to use two-dimensional (2-D) contour correlations (Cohen, Jain, & Zaidi, 2010). That leaves dynamic depth matching across the unoccluded views as the main possibility. We examined the role of stereo cues in extracting motion of partially occluded and deforming three-dimensional (3-D) objects, simulated by disk-shaped random-dot stereograms set at randomly assigned depths and placed uniformly around a circle. The stereo-disparities of the disks were temporally oscillated to simulate clockwise or counterclockwise rotation of the global shape. To dynamically deform the global shape, random disparity perturbation was added to each disk's depth on each stimulus frame. At low perturbation, observers reported rotation directions consistent with the global shape, even against local motion cues, but performance deteriorated at high perturbation. Using 3-D global shape correlations, we formulated an optimal Bayesian discriminator for rotation direction. Based on rotation discrimination thresholds, human observers were 75% as efficient as the optimal model, demonstrating that global shapes derived from stereo cues facilitate inferences of object motions. To complement reports of stereo and motion integration in extrastriate cortex, our results suggest the possibilities that disparity selectivity and feature tracking are linked, or that global motion selective neurons can be driven purely from disparity cues. PMID:23325345

Depth Cue Integration in an Active Control Paradigm

NASA Technical Reports Server (NTRS)

Kaiser, Mary K.; Sweet, Barabara T.; Shafto, Meredith; Null, Cynthia H. (Technical Monitor)

1995-01-01

Numerous models of depth cue integration have been proposed. Of particular interest is how the visual system processes discrepent cues, as might arise when viewing synthetic displays. A powerful paradigm for examining this integration process can be adapted from manual control research. This methodology introduces independent disturbances in the candidate cues, then performs spectral analysis of subjects' resulting motoric responses (e.g., depth matching). We will describe this technique and present initial findings.

Rethinking human visual attention: spatial cueing effects and optimality of decisions by honeybees, monkeys and humans.

PubMed

Eckstein, Miguel P; Mack, Stephen C; Liston, Dorion B; Bogush, Lisa; Menzel, Randolf; Krauzlis, Richard J

2013-06-07

Visual attention is commonly studied by using visuo-spatial cues indicating probable locations of a target and assessing the effect of the validity of the cue on perceptual performance and its neural correlates. Here, we adapt a cueing task to measure spatial cueing effects on the decisions of honeybees and compare their behavior to that of humans and monkeys in a similarly structured two-alternative forced-choice perceptual task. Unlike the typical cueing paradigm in which the stimulus strength remains unchanged within a block of trials, for the monkey and human studies we randomized the contrast of the signal to simulate more real world conditions in which the organism is uncertain about the strength of the signal. A Bayesian ideal observer that weights sensory evidence from cued and uncued locations based on the cue validity to maximize overall performance is used as a benchmark of comparison against the three animals and other suboptimal models: probability matching, ignore the cue, always follow the cue, and an additive bias/single decision threshold model. We find that the cueing effect is pervasive across all three species but is smaller in size than that shown by the Bayesian ideal observer. Humans show a larger cueing effect than monkeys and bees show the smallest effect. The cueing effect and overall performance of the honeybees allows rejection of the models in which the bees are ignoring the cue, following the cue and disregarding stimuli to be discriminated, or adopting a probability matching strategy. Stimulus strength uncertainty also reduces the theoretically predicted variation in cueing effect with stimulus strength of an optimal Bayesian observer and diminishes the size of the cueing effect when stimulus strength is low. A more biologically plausible model that includes an additive bias to the sensory response from the cued location, although not mathematically equivalent to the optimal observer for the case stimulus strength uncertainty, can approximate the benefits of the more computationally complex optimal Bayesian model. We discuss the implications of our findings on the field's common conceptualization of covert visual attention in the cueing task and what aspects, if any, might be unique to humans. Copyright © 2013 Elsevier Ltd. All rights reserved.

A systematic comparison between visual cues for boundary detection.

PubMed

Mély, David A; Kim, Junkyung; McGill, Mason; Guo, Yuliang; Serre, Thomas

2016-03-01

The detection of object boundaries is a critical first step for many visual processing tasks. Multiple cues (we consider luminance, color, motion and binocular disparity) available in the early visual system may signal object boundaries but little is known about their relative diagnosticity and how to optimally combine them for boundary detection. This study thus aims at understanding how early visual processes inform boundary detection in natural scenes. We collected color binocular video sequences of natural scenes to construct a video database. Each scene was annotated with two full sets of ground-truth contours (one set limited to object boundaries and another set which included all edges). We implemented an integrated computational model of early vision that spans all considered cues, and then assessed their diagnosticity by training machine learning classifiers on individual channels. Color and luminance were found to be most diagnostic while stereo and motion were least. Combining all cues yielded a significant improvement in accuracy beyond that of any cue in isolation. Furthermore, the accuracy of individual cues was found to be a poor predictor of their unique contribution for the combination. This result suggested a complex interaction between cues, which we further quantified using regularization techniques. Our systematic assessment of the accuracy of early vision models for boundary detection together with the resulting annotated video dataset should provide a useful benchmark towards the development of higher-level models of visual processing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimal visuotactile integration for velocity discrimination of self-hand movements

PubMed Central

Chancel, M.; Blanchard, C.; Guerraz, M.; Montagnini, A.

2016-01-01

Illusory hand movements can be elicited by a textured disk or a visual pattern rotating under one's hand, while proprioceptive inputs convey immobility information (Blanchard C, Roll R, Roll JP, Kavounoudias A. PLoS One 8: e62475, 2013). Here, we investigated whether visuotactile integration can optimize velocity discrimination of illusory hand movements in line with Bayesian predictions. We induced illusory movements in 15 volunteers by visual and/or tactile stimulation delivered at six angular velocities. Participants had to compare hand illusion velocities with a 5°/s hand reference movement in an alternative forced choice paradigm. Results showed that the discrimination threshold decreased in the visuotactile condition compared with unimodal (visual or tactile) conditions, reflecting better bimodal discrimination. The perceptual strength (gain) of the illusions also increased: the stimulation required to give rise to a 5°/s illusory movement was slower in the visuotactile condition compared with each of the two unimodal conditions. The maximum likelihood estimation model satisfactorily predicted the improved discrimination threshold but not the increase in gain. When we added a zero-centered prior, reflecting immobility information, the Bayesian model did actually predict the gain increase but systematically overestimated it. Interestingly, the predicted gains better fit the visuotactile performances when a proprioceptive noise was generated by covibrating antagonist wrist muscles. These findings show that kinesthetic information of visual and tactile origins is optimally integrated to improve velocity discrimination of self-hand movements. However, a Bayesian model alone could not fully describe the illusory phenomenon pointing to the crucial importance of the omnipresent muscle proprioceptive cues with respect to other sensory cues for kinesthesia. PMID:27385802

Language Processing as Cue Integration: Grounding the Psychology of Language in Perception and Neurophysiology

PubMed Central

Martin, Andrea E.

2016-01-01

I argue that cue integration, a psychophysiological mechanism from vision and multisensory perception, offers a computational linking hypothesis between psycholinguistic theory and neurobiological models of language. I propose that this mechanism, which incorporates probabilistic estimates of a cue's reliability, might function in language processing from the perception of a phoneme to the comprehension of a phrase structure. I briefly consider the implications of the cue integration hypothesis for an integrated theory of language that includes acquisition, production, dialogue and bilingualism, while grounding the hypothesis in canonical neural computation. PMID:26909051

Optimal multisensory decision-making in a reaction-time task.

PubMed

Drugowitsch, Jan; DeAngelis, Gregory C; Klier, Eliana M; Angelaki, Dora E; Pouget, Alexandre

2014-06-14

Humans and animals can integrate sensory evidence from various sources to make decisions in a statistically near-optimal manner, provided that the stimulus presentation time is fixed across trials. Little is known about whether optimality is preserved when subjects can choose when to make a decision (reaction-time task), nor when sensory inputs have time-varying reliability. Using a reaction-time version of a visual/vestibular heading discrimination task, we show that behavior is clearly sub-optimal when quantified with traditional optimality metrics that ignore reaction times. We created a computational model that accumulates evidence optimally across both cues and time, and trades off accuracy with decision speed. This model quantitatively explains subjects's choices and reaction times, supporting the hypothesis that subjects do, in fact, accumulate evidence optimally over time and across sensory modalities, even when the reaction time is under the subject's control.

The contribution of visual information to the perception of speech in noise with and without informative temporal fine structure

PubMed Central

Stacey, Paula C.; Kitterick, Pádraig T.; Morris, Saffron D.; Sumner, Christian J.

2017-01-01

Understanding what is said in demanding listening situations is assisted greatly by looking at the face of a talker. Previous studies have observed that normal-hearing listeners can benefit from this visual information when a talker's voice is presented in background noise. These benefits have also been observed in quiet listening conditions in cochlear-implant users, whose device does not convey the informative temporal fine structure cues in speech, and when normal-hearing individuals listen to speech processed to remove these informative temporal fine structure cues. The current study (1) characterised the benefits of visual information when listening in background noise; and (2) used sine-wave vocoding to compare the size of the visual benefit when speech is presented with or without informative temporal fine structure. The accuracy with which normal-hearing individuals reported words in spoken sentences was assessed across three experiments. The availability of visual information and informative temporal fine structure cues was varied within and across the experiments. The results showed that visual benefit was observed using open- and closed-set tests of speech perception. The size of the benefit increased when informative temporal fine structure cues were removed. This finding suggests that visual information may play an important role in the ability of cochlear-implant users to understand speech in many everyday situations. Models of audio-visual integration were able to account for the additional benefit of visual information when speech was degraded and suggested that auditory and visual information was being integrated in a similar way in all conditions. The modelling results were consistent with the notion that audio-visual benefit is derived from the optimal combination of auditory and visual sensory cues. PMID:27085797

Evaluating the effects of delivering integrated kinesthetic and tactile cues to individuals with unilateral hemiparetic stroke during overground walking.

PubMed

Afzal, Muhammad Raheel; Pyo, Sanghun; Oh, Min-Kyun; Park, Young Sook; Yoon, Jungwon

2018-04-16

Integration of kinesthetic and tactile cues for application to post-stroke gait rehabilitation is a novel concept which needs to be explored. The combined provision of haptic cues may result in collective improvement of gait parameters such as symmetry, balance and muscle activation patterns. Our proposed integrated cue system can offer a cost-effective and voluntary gait training experience for rehabilitation of subjects with unilateral hemiparetic stroke. Ten post-stroke ambulatory subjects participated in a 10 m walking trial while utilizing the haptic cues (either alone or integrated application), at their preferred and increased gait speeds. In the system a haptic cane device (HCD) provided kinesthetic perception and a vibrotactile feedback device (VFD) provided tactile cue on the paretic leg for gait modification. Balance, gait symmetry and muscle activity were analyzed to identify the benefits of utilizing the proposed system. When using kinesthetic cues, either alone or integrated with a tactile cue, an increase in the percentage of non-paretic peak activity in the paretic muscles was observed at the preferred gait speed (vastus medialis obliquus: p <  0.001, partial eta squared (η 2 ) = 0.954; semitendinosus p <  0.001, partial η 2  = 0.793) and increased gait speeds (vastus medialis obliquus: p <  0.001, partial η 2  = 0.881; semitendinosus p = 0.028, partial η 2  = 0.399). While using HCD and VFD (individual and integrated applications), subjects could walk at their preferred and increased gait speeds without disrupting trunk balance in the mediolateral direction. The temporal stance symmetry ratio was improved when using tactile cues, either alone or integrated with a kinesthetic cue, at their preferred gait speed (p <  0.001, partial η 2  = 0.702). When combining haptic cues, the subjects walked at their preferred gait speed with increased temporal stance symmetry and paretic muscle activity affecting their balance. Similar improvements were observed at higher gait speeds. The efficacy of the proposed system is influenced by gait speed. Improvements were observed at a 20% increased gait speed, whereas, a plateau effect was observed at a 40% increased gait speed. These results imply that integration of haptic cues may benefit post-stroke gait rehabilitation by inducing simultaneous improvements in gait symmetry and muscle activity.

Impaired movement timing in neurological disorders: rehabilitation and treatment strategies.

PubMed

Hove, Michael J; Keller, Peter E

2015-03-01

Timing abnormalities have been reported in many neurological disorders, including Parkinson's disease (PD). In PD, motor-timing impairments are especially debilitating in gait. Despite impaired audiomotor synchronization, PD patients' gait improves when they walk with an auditory metronome or with music. Building on that research, we make recommendations for optimizing sensory cues to improve the efficacy of rhythmic cuing in gait rehabilitation. Adaptive rhythmic metronomes (that synchronize with the patient's walking) might be especially effective. In a recent study we showed that adaptive metronomes synchronized consistently with PD patients' footsteps without requiring attention; this improved stability and reinstated healthy gait dynamics. Other strategies could help optimize sensory cues for gait rehabilitation. Groove music strongly engages the motor system and induces movement; bass-frequency tones are associated with movement and provide strong timing cues. Thus, groove and bass-frequency pulses could deliver potent rhythmic cues. These strategies capitalize on the close neural connections between auditory and motor networks; and auditory cues are typically preferred. However, moving visual cues greatly improve visuomotor synchronization and could warrant examination in gait rehabilitation. Together, a treatment approach that employs groove, auditory, bass-frequency, and adaptive (GABA) cues could help optimize rhythmic sensory cues for treating motor and timing deficits. © 2014 New York Academy of Sciences.

Visual-haptic integration with pliers and tongs: signal “weights” take account of changes in haptic sensitivity caused by different tools

PubMed Central

Takahashi, Chie; Watt, Simon J.

2014-01-01

When we hold an object while looking at it, estimates from visual and haptic cues to size are combined in a statistically optimal fashion, whereby the “weight” given to each signal reflects their relative reliabilities. This allows object properties to be estimated more precisely than would otherwise be possible. Tools such as pliers and tongs systematically perturb the mapping between object size and the hand opening. This could complicate visual-haptic integration because it may alter the reliability of the haptic signal, thereby disrupting the determination of appropriate signal weights. To investigate this we first measured the reliability of haptic size estimates made with virtual pliers-like tools (created using a stereoscopic display and force-feedback robots) with different “gains” between hand opening and object size. Haptic reliability in tool use was straightforwardly determined by a combination of sensitivity to changes in hand opening and the effects of tool geometry. The precise pattern of sensitivity to hand opening, which violated Weber's law, meant that haptic reliability changed with tool gain. We then examined whether the visuo-motor system accounts for these reliability changes. We measured the weight given to visual and haptic stimuli when both were available, again with different tool gains, by measuring the perceived size of stimuli in which visual and haptic sizes were varied independently. The weight given to each sensory cue changed with tool gain in a manner that closely resembled the predictions of optimal sensory integration. The results are consistent with the idea that different tool geometries are modeled by the brain, allowing it to calculate not only the distal properties of objects felt with tools, but also the certainty with which those properties are known. These findings highlight the flexibility of human sensory integration and tool-use, and potentially provide an approach for optimizing the design of visual-haptic devices. PMID:24592245

Counterbalancing in smoking cue research: a critical analysis.

PubMed

Sayette, Michael A; Griffin, Kasey M; Sayers, W Michael

2010-11-01

Cue exposure research has been used to examine key issues in smoking research, such as predicting relapse, testing new medications, investigating the neurobiology of nicotine dependence, and examining reactivity among smokers with comorbid psychopathologies. Determining the order that cues are presented is one of the most critical steps in the design of these investigations. It is widely assumed that cue exposure studies should counterbalance the order in which smoking and control (neutral) cues are presented. This article examines the premises underlying the use of counterbalancing in experimental research, and it evaluates the degree to which counterbalancing is appropriate in smoking cue exposure studies. We reviewed the available literature on the use of counterbalancing techniques in human smoking cue exposure research. Many studies counterbalancing order of cues have not provided critical analyses to determine whether this approach was appropriate. Studies that have reported relevant data, however, suggest that order of cue presentation interacts with type of cue (smoking vs. control), which raises concerns about the utility of counterbalancing. Primarily, this concern arises from potential carryover effects, in which exposure to smoking cues affects subsequent responding to neutral cues. Cue type by order of cue interactions may compromise the utility of counterbalancing. Unfortunately, there is no obvious alternative that is optimal across studies. Strengths and limitations of several alternative designs are considered, and key questions are identified to advance understanding of the optimal conditions for conducting smoking cue exposure studies.

Social Vision: Functional Forecasting and the Integration of Compound Social Cues

PubMed Central

Adams, Reginald B.; Kveraga, Kestutis

2017-01-01

For decades the study of social perception was largely compartmentalized by type of social cue: race, gender, emotion, eye gaze, body language, facial expression etc. This was partly due to good scientific practice (e.g., controlling for extraneous variability), and partly due to assumptions that each type of social cue was functionally distinct from others. Herein, we present a functional forecast approach to understanding compound social cue processing that emphasizes the importance of shared social affordances across various cues (see too Adams, Franklin, Nelson, & Stevenson, 2010; Adams & Nelson, 2011; Weisbuch & Adams, 2012). We review the traditional theories of emotion and face processing that argued for dissociable and noninteracting pathways (e.g., for specific emotional expressions, gaze, identity cues), as well as more recent evidence for combinatorial processing of social cues. We argue here that early, and presumably reflexive, visual integration of such cues is necessary for adaptive behavioral responding to others. In support of this claim, we review contemporary work that reveals a flexible visual system, one that readily incorporates meaningful contextual influences in even nonsocial visual processing, thereby establishing the functional and neuroanatomical bases necessary for compound social cue integration. Finally, we explicate three likely mechanisms driving such integration. Together, this work implicates a role for cognitive penetrability in visual perceptual abilities that have often been (and in some cases still are) ascribed to direct encapsulated perceptual processes. PMID:29242738

Contextual cueing improves attentional guidance, even when guidance is supposedly optimal.

PubMed

Harris, Anthony M; Remington, Roger W

2017-05-01

Visual search through previously encountered contexts typically produces reduced reaction times compared with search through novel contexts. This contextual cueing benefit is well established, but there is debate regarding its underlying mechanisms. Eye-tracking studies have consistently shown reduced number of fixations with repetition, supporting improvements in attentional guidance as the source of contextual cueing. However, contextual cueing benefits have been shown in conditions in which attentional guidance should already be optimal-namely, when attention is captured to the target location by an abrupt onset, or under pop-out conditions. These results have been used to argue for a response-related account of contextual cueing. Here, we combine eye tracking with response time to examine the mechanisms behind contextual cueing in spatially cued and pop-out conditions. Three experiments find consistent response time benefits with repetition, which appear to be driven almost entirely by a reduction in number of fixations, supporting improved attentional guidance as the mechanism behind contextual cueing. No differences were observed in the time between fixating the target and responding-our proxy for response related processes. Furthermore, the correlation between contextual cueing magnitude and the reduction in number of fixations on repeated contexts approaches 1. These results argue strongly that attentional guidance is facilitated by familiar search contexts, even when guidance is near-optimal. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A treat for the eyes. An eye-tracking study on children's attention to unhealthy and healthy food cues in media content.

PubMed

Spielvogel, Ines; Matthes, Jörg; Naderer, Brigitte; Karsay, Kathrin

2018-06-01

Based on cue reactivity theory, food cues embedded in media content can lead to physiological and psychological responses in children. Research suggests that unhealthy food cues are represented more extensively and interactively in children's media environments than healthy ones. However, it is not clear to this date whether children react differently to unhealthy compared to healthy food cues. In an experimental study with 56 children (55.4% girls; M age  = 8.00, SD = 1.58), we used eye-tracking to determine children's attention to unhealthy and healthy food cues embedded in a narrative cartoon movie. Besides varying the food type (i.e., healthy vs. unhealthy), we also manipulated the integration levels of food cues with characters (i.e., level of food integration; no interaction vs. handling vs. consumption), and we assessed children's individual susceptibility factors by measuring the impact of their hunger level. Our results indicated that unhealthy food cues attract children's visual attention to a larger extent than healthy cues. However, their initial visual interest did not differ between unhealthy and healthy food cues. Furthermore, an increase in the level of food integration led to an increase in visual attention. Our findings showed no moderating impact of hunger. We conclude that especially unhealthy food cues with an interactive connection trigger cue reactivity in children. Copyright © 2018 Elsevier Ltd. All rights reserved.

Counterbalancing in Smoking Cue Research: A Critical Analysis

PubMed Central

Griffin, Kasey M.; Sayers, W. Michael

2010-01-01

Introduction: Cue exposure research has been used to examine key issues in smoking research, such as predicting relapse, testing new medications, investigating the neurobiology of nicotine dependence, and examining reactivity among smokers with comorbid psychopathologies. Determining the order that cues are presented is one of the most critical steps in the design of these investigations. It is widely assumed that cue exposure studies should counterbalance the order in which smoking and control (neutral) cues are presented. This article examines the premises underlying the use of counterbalancing in experimental research, and it evaluates the degree to which counterbalancing is appropriate in smoking cue exposure studies. Methods: We reviewed the available literature on the use of counterbalancing techniques in human smoking cue exposure research. Results: Many studies counterbalancing order of cues have not provided critical analyses to determine whether this approach was appropriate. Studies that have reported relevant data, however, suggest that order of cue presentation interacts with type of cue (smoking vs. control), which raises concerns about the utility of counterbalancing. Primarily, this concern arises from potential carryover effects, in which exposure to smoking cues affects subsequent responding to neutral cues. Conclusions: Cue type by order of cue interactions may compromise the utility of counterbalancing. Unfortunately, there is no obvious alternative that is optimal across studies. Strengths and limitations of several alternative designs are considered, and key questions are identified to advance understanding of the optimal conditions for conducting smoking cue exposure studies. PMID:20884695

A simple approach to ignoring irrelevant variables by population decoding based on multisensory neurons

PubMed Central

Kim, HyungGoo R.; Pitkow, Xaq; Angelaki, Dora E.

2016-01-01

Sensory input reflects events that occur in the environment, but multiple events may be confounded in sensory signals. For example, under many natural viewing conditions, retinal image motion reflects some combination of self-motion and movement of objects in the world. To estimate one stimulus event and ignore others, the brain can perform marginalization operations, but the neural bases of these operations are poorly understood. Using computational modeling, we examine how multisensory signals may be processed to estimate the direction of self-motion (i.e., heading) and to marginalize out effects of object motion. Multisensory neurons represent heading based on both visual and vestibular inputs and come in two basic types: “congruent” and “opposite” cells. Congruent cells have matched heading tuning for visual and vestibular cues and have been linked to perceptual benefits of cue integration during heading discrimination. Opposite cells have mismatched visual and vestibular heading preferences and are ill-suited for cue integration. We show that decoding a mixed population of congruent and opposite cells substantially reduces errors in heading estimation caused by object motion. In addition, we present a general formulation of an optimal linear decoding scheme that approximates marginalization and can be implemented biologically by simple reinforcement learning mechanisms. We also show that neural response correlations induced by task-irrelevant variables may greatly exceed intrinsic noise correlations. Overall, our findings suggest a general computational strategy by which neurons with mismatched tuning for two different sensory cues may be decoded to perform marginalization operations that dissociate possible causes of sensory inputs. PMID:27334948

Bayesian Cue Integration as a Developmental Outcome of Reward Mediated Learning

PubMed Central

Weisswange, Thomas H.; Rothkopf, Constantin A.; Rodemann, Tobias; Triesch, Jochen

2011-01-01

Average human behavior in cue combination tasks is well predicted by Bayesian inference models. As this capability is acquired over developmental timescales, the question arises, how it is learned. Here we investigated whether reward dependent learning, that is well established at the computational, behavioral, and neuronal levels, could contribute to this development. It is shown that a model free reinforcement learning algorithm can indeed learn to do cue integration, i.e. weight uncertain cues according to their respective reliabilities and even do so if reliabilities are changing. We also consider the case of causal inference where multimodal signals can originate from one or multiple separate objects and should not always be integrated. In this case, the learner is shown to develop a behavior that is closest to Bayesian model averaging. We conclude that reward mediated learning could be a driving force for the development of cue integration and causal inference. PMID:21750717

Optimal multiguidance integration in insect navigation.

PubMed

Hoinville, Thierry; Wehner, Rüdiger

2018-03-13

In the last decades, desert ants have become model organisms for the study of insect navigation. In finding their way, they use two major navigational routines: path integration using a celestial compass and landmark guidance based on sets of panoramic views of the terrestrial environment. It has been claimed that this information would enable the insect to acquire and use a centralized cognitive map of its foraging terrain. Here, we present a decentralized architecture, in which the concurrently operating path integration and landmark guidance routines contribute optimally to the directions to be steered, with "optimal" meaning maximizing the certainty (reliability) of the combined information. At any one time during its journey, the animal computes a path integration (global) vector and landmark guidance (local) vector, in which the length of each vector is proportional to the certainty of the individual estimates. Hence, these vectors represent the limited knowledge that the navigator has at any one place about the direction of the goal. The sum of the global and local vectors indicates the navigator's optimal directional estimate. Wherever applied, this decentralized model architecture is sufficient to simulate the results of quite a number of diverse cue-conflict experiments, which have recently been performed in various behavioral contexts by different authors in both desert ants and honeybees. They include even those experiments that have deliberately been designed by former authors to strengthen the evidence for a metric cognitive map in bees.

Attention to sound improves auditory reliability in audio-tactile spatial optimal integration.

PubMed

Vercillo, Tiziana; Gori, Monica

2015-01-01

The role of attention on multisensory processing is still poorly understood. In particular, it is unclear whether directing attention toward a sensory cue dynamically reweights cue reliability during integration of multiple sensory signals. In this study, we investigated the impact of attention in combining audio-tactile signals in an optimal fashion. We used the Maximum Likelihood Estimation (MLE) model to predict audio-tactile spatial localization on the body surface. We developed a new audio-tactile device composed by several small units, each one consisting of a speaker and a tactile vibrator independently controllable by external software. We tested participants in an attentional and a non-attentional condition. In the attentional experiment, participants performed a dual task paradigm: they were required to evaluate the duration of a sound while performing an audio-tactile spatial task. Three unisensory or multisensory stimuli, conflictual or not conflictual sounds and vibrations arranged along the horizontal axis, were presented sequentially. In the primary task participants had to evaluate in a space bisection task the position of the second stimulus (the probe) with respect to the others (the standards). In the secondary task they had to report occasionally changes in duration of the second auditory stimulus. In the non-attentional task participants had only to perform the primary task (space bisection). Our results showed an enhanced auditory precision (and auditory weights) in the auditory attentional condition with respect to the control non-attentional condition. The results of this study support the idea that modality-specific attention modulates multisensory integration.

Visual and auditory cue integration for the generation of saccadic eye movements in monkeys and lever pressing in humans.

PubMed

Schiller, Peter H; Kwak, Michelle C; Slocum, Warren M

2012-08-01

This study examined how effectively visual and auditory cues can be integrated in the brain for the generation of motor responses. The latencies with which saccadic eye movements are produced in humans and monkeys form, under certain conditions, a bimodal distribution, the first mode of which has been termed express saccades. In humans, a much higher percentage of express saccades is generated when both visual and auditory cues are provided compared with the single presentation of these cues [H. C. Hughes et al. (1994) J. Exp. Psychol. Hum. Percept. Perform., 20, 131-153]. In this study, we addressed two questions: first, do monkeys also integrate visual and auditory cues for express saccade generation as do humans and second, does such integration take place in humans when, instead of eye movements, the task is to press levers with fingers? Our results show that (i) in monkeys, as in humans, the combined visual and auditory cues generate a much higher percentage of express saccades than do singly presented cues and (ii) the latencies with which levers are pressed by humans are shorter when both visual and auditory cues are provided compared with the presentation of single cues, but the distribution in all cases is unimodal; response latencies in the express range seen in the execution of saccadic eye movements are not obtained with lever pressing. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Bridging the gap between theories of sensory cue integration and the physiology of multisensory neurons

PubMed Central

Fetsch, Christopher R.

2013-01-01

The richness of perceptual experience, as well as its usefulness for guiding behavior, depends upon the synthesis of information across multiple senses. Recent decades have witnessed a surge in our understanding of how the brain combines sensory signals, or cues. Much of this research has been guided by one of two distinct approaches, one driven primarily by neurophysiological observations, the other guided by principles of mathematical psychology and psychophysics. Conflicting results and interpretations have contributed to a conceptual gap between psychophysical and physiological accounts of cue integration, but recent studies of visual-vestibular cue integration have narrowed this gap considerably. PMID:23686172

Spectro-temporal cues enhance modulation sensitivity in cochlear implant users

PubMed Central

Zheng, Yi; Escabí, Monty; Litovsky, Ruth Y.

2018-01-01

Although speech understanding is highly variable amongst cochlear implants (CIs) subjects, the remarkably high speech recognition performance of many CI users is unexpected and not well understood. Numerous factors, including neural health and degradation of the spectral information in the speech signal of CIs, likely contribute to speech understanding. We studied the ability to use spectro-temporal modulations, which may be critical for speech understanding and discrimination, and hypothesize that CI users adopt a different perceptual strategy than normal-hearing (NH) individuals, whereby they rely more heavily on joint spectro-temporal cues to enhance detection of auditory cues. Modulation detection sensitivity was studied in CI users and NH subjects using broadband “ripple” stimuli that were modulated spectrally, temporally, or jointly, i.e., spectro-temporally. The spectro-temporal modulation transfer functions of CI users and NH subjects was decomposed into spectral and temporal dimensions and compared to those subjects’ spectral-only and temporal-only modulation transfer functions. In CI users, the joint spectro-temporal sensitivity was better than that predicted by spectral-only and temporal-only sensitivity, indicating a heightened spectro-temporal sensitivity. Such an enhancement through the combined integration of spectral and temporal cues was not observed in NH subjects. The unique use of spectro-temporal cues by CI patients can yield benefits for use of cues that are important for speech understanding. This finding has implications for developing sound processing strategies that may rely on joint spectro-temporal modulations to improve speech comprehension of CI users, and the findings of this study may be valuable for developing clinical assessment tools to optimize CI processor performance. PMID:28601530

Modeling of Depth Cue Integration in Manual Control Tasks

NASA Technical Reports Server (NTRS)

Sweet, Barbara T.; Kaiser, Mary K.; Davis, Wendy

2003-01-01

Psychophysical research has demonstrated that human observers utilize a variety of visual cues to form a perception of three-dimensional depth. However, most of these studies have utilized a passive judgement paradigm, and failed to consider depth-cue integration as a dynamic and task-specific process. In the current study, we developed and experimentally validated a model of manual control of depth that examines how two potential cues (stereo disparity and relative size) are utilized in both first- and second-order active depth control tasks. We found that stereo disparity plays the dominate role for determining depth position, while relative size dominates perception of depth velocity. Stereo disparity also plays a reduced role when made less salient (i.e., when viewing distance is increased). Manual control models predict that position information is sufficient for first-order control tasks, while velocity information is required to perform a second-order control task. Thus, the rules for depth-cue integration in active control tasks are dependent on both task demands and cue quality.

Weighting of Amplitude and Formant Rise Time Cues by School-Aged Children: A Mismatch Negativity Study

ERIC Educational Resources Information Center

Varghese, Peter; Kalashnikova, Marina; Burnham, Denis

2018-01-01

Purpose: An important skill in the development of speech perception is to apply optimal weights to acoustic cues so that phonemic information is recovered from speech with minimum effort. Here, we investigated the development of acoustic cue weighting of amplitude rise time (ART) and formant rise time (FRT) cues in children as measured by mismatch…

Music and metronome cues produce different effects on gait spatiotemporal measures but not gait variability in healthy older adults.

PubMed

Wittwer, Joanne E; Webster, Kate E; Hill, Keith

2013-02-01

Rhythmic auditory cues including music and metronome beats have been used, sometimes interchangeably, to improve disordered gait arising from a range of clinical conditions. There has been limited investigation into whether there are optimal cue types. Different cue types have produced inconsistent effects across groups which differed in both age and clinical condition. The possible effect of normal ageing on response to different cue types has not been reported for gait. The aim of this study was to determine the effects of both rhythmic music and metronome cues on gait spatiotemporal measures (including variability) in healthy older people. Twelve women and seven men (>65 years) walked on an instrumented walkway at comfortable pace and then in time to each of rhythmic music and metronome cues at comfortable pace stepping frequency. Music but not metronome cues produced a significant increase in group mean gait velocity of 4.6 cm/s, due mostly to a significant increase in group mean stride length of 3.1cm. Both cue types produced a significant but small increase in cadence of 1 step/min. Mean spatio-temporal variability was low at baseline and did not increase with either cue type suggesting cues did not disrupt gait timing. Study findings suggest music and metronome cues may not be used interchangeably and cue type as well as frequency should be considered when evaluating effects of rhythmic auditory cueing on gait. Further work is required to determine whether optimal cue types and frequencies to improve walking in different clinical groups can be identified. Copyright © 2012 Elsevier B.V. All rights reserved.

Persistent fluctuations in stride intervals under fractal auditory stimulation.

PubMed

Marmelat, Vivien; Torre, Kjerstin; Beek, Peter J; Daffertshofer, Andreas

2014-01-01

Stride sequences of healthy gait are characterized by persistent long-range correlations, which become anti-persistent in the presence of an isochronous metronome. The latter phenomenon is of particular interest because auditory cueing is generally considered to reduce stride variability and may hence be beneficial for stabilizing gait. Complex systems tend to match their correlation structure when synchronizing. In gait training, can one capitalize on this tendency by using a fractal metronome rather than an isochronous one? We examined whether auditory cues with fractal variations in inter-beat intervals yield similar fractal inter-stride interval variability as isochronous auditory cueing in two complementary experiments. In Experiment 1, participants walked on a treadmill while being paced by either an isochronous or a fractal metronome with different variation strengths between beats in order to test whether participants managed to synchronize with a fractal metronome and to determine the necessary amount of variability for participants to switch from anti-persistent to persistent inter-stride intervals. Participants did synchronize with the metronome despite its fractal randomness. The corresponding coefficient of variation of inter-beat intervals was fixed in Experiment 2, in which participants walked on a treadmill while being paced by non-isochronous metronomes with different scaling exponents. As expected, inter-stride intervals showed persistent correlations similar to self-paced walking only when cueing contained persistent correlations. Our results open up a new window to optimize rhythmic auditory cueing for gait stabilization by integrating fractal fluctuations in the inter-beat intervals.

Persistent Fluctuations in Stride Intervals under Fractal Auditory Stimulation

PubMed Central

Marmelat, Vivien; Torre, Kjerstin; Beek, Peter J.; Daffertshofer, Andreas

2014-01-01

Stride sequences of healthy gait are characterized by persistent long-range correlations, which become anti-persistent in the presence of an isochronous metronome. The latter phenomenon is of particular interest because auditory cueing is generally considered to reduce stride variability and may hence be beneficial for stabilizing gait. Complex systems tend to match their correlation structure when synchronizing. In gait training, can one capitalize on this tendency by using a fractal metronome rather than an isochronous one? We examined whether auditory cues with fractal variations in inter-beat intervals yield similar fractal inter-stride interval variability as isochronous auditory cueing in two complementary experiments. In Experiment 1, participants walked on a treadmill while being paced by either an isochronous or a fractal metronome with different variation strengths between beats in order to test whether participants managed to synchronize with a fractal metronome and to determine the necessary amount of variability for participants to switch from anti-persistent to persistent inter-stride intervals. Participants did synchronize with the metronome despite its fractal randomness. The corresponding coefficient of variation of inter-beat intervals was fixed in Experiment 2, in which participants walked on a treadmill while being paced by non-isochronous metronomes with different scaling exponents. As expected, inter-stride intervals showed persistent correlations similar to self-paced walking only when cueing contained persistent correlations. Our results open up a new window to optimize rhythmic auditory cueing for gait stabilization by integrating fractal fluctuations in the inter-beat intervals. PMID:24651455

Evidence for cue-independent spatial representation in the human auditory cortex during active listening.

PubMed

Higgins, Nathan C; McLaughlin, Susan A; Rinne, Teemu; Stecker, G Christopher

2017-09-05

Few auditory functions are as important or as universal as the capacity for auditory spatial awareness (e.g., sound localization). That ability relies on sensitivity to acoustical cues-particularly interaural time and level differences (ITD and ILD)-that correlate with sound-source locations. Under nonspatial listening conditions, cortical sensitivity to ITD and ILD takes the form of broad contralaterally dominated response functions. It is unknown, however, whether that sensitivity reflects representations of the specific physical cues or a higher-order representation of auditory space (i.e., integrated cue processing), nor is it known whether responses to spatial cues are modulated by active spatial listening. To investigate, sensitivity to parametrically varied ITD or ILD cues was measured using fMRI during spatial and nonspatial listening tasks. Task type varied across blocks where targets were presented in one of three dimensions: auditory location, pitch, or visual brightness. Task effects were localized primarily to lateral posterior superior temporal gyrus (pSTG) and modulated binaural-cue response functions differently in the two hemispheres. Active spatial listening (location tasks) enhanced both contralateral and ipsilateral responses in the right hemisphere but maintained or enhanced contralateral dominance in the left hemisphere. Two observations suggest integrated processing of ITD and ILD. First, overlapping regions in medial pSTG exhibited significant sensitivity to both cues. Second, successful classification of multivoxel patterns was observed for both cue types and-critically-for cross-cue classification. Together, these results suggest a higher-order representation of auditory space in the human auditory cortex that at least partly integrates the specific underlying cues.

The left dorsolateral prefrontal cortex and caudate pathway: New evidence for cue-induced craving of smokers.

PubMed

Yuan, Kai; Yu, Dahua; Bi, Yanzhi; Wang, Ruonan; Li, Min; Zhang, Yajuan; Dong, Minghao; Zhai, Jinquan; Li, Yangding; Lu, Xiaoqi; Tian, Jie

2017-09-01

Although the activation of the prefrontal cortex (PFC) and the striatum had been found in smoking cue induced craving task, whether and how the functional interactions and white matter integrity between these brain regions contribute to craving processing during smoking cue exposure remains unknown. Twenty-five young male smokers and 26 age- and gender-matched nonsmokers participated in the smoking cue-reactivity task. Craving related brain activation was extracted and psychophysiological interactions (PPI) analysis was used to specify the PFC-efferent pathways contributed to smoking cue-induced craving. Diffusion tensor imaging (DTI) and probabilistic tractography was used to explore whether the fiber connectivity strength facilitated functional coupling of the circuit with the smoking cue-induced craving. The PPI analysis revealed the negative functional coupling of the left dorsolateral prefrontal cortex (DLPFC) and the caudate during smoking cue induced craving task, which positively correlated with the craving score. Neither significant activation nor functional connectivity in smoking cue exposure task was detected in nonsmokers. DTI analyses revealed that fiber tract integrity negatively correlated with functional coupling in the DLPFC-caudate pathway and activation of the caudate induced by smoking cue in smokers. Moreover, the relationship between the fiber connectivity integrity of the left DLPFC-caudate and smoking cue induced caudate activation can be fully mediated by functional coupling strength of this circuit in smokers. The present study highlighted the left DLPFC-caudate pathway in smoking cue-induced craving in smokers, which may reflect top-down prefrontal modulation of striatal reward processing in smoking cue induced craving processing. Hum Brain Mapp 38:4644-4656, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Age Differences in Visual-Auditory Self-Motion Perception during a Simulated Driving Task

PubMed Central

Ramkhalawansingh, Robert; Keshavarz, Behrang; Haycock, Bruce; Shahab, Saba; Campos, Jennifer L.

2016-01-01

Recent evidence suggests that visual-auditory cue integration may change as a function of age such that integration is heightened among older adults. Our goal was to determine whether these changes in multisensory integration are also observed in the context of self-motion perception under realistic task constraints. Thus, we developed a simulated driving paradigm in which we provided older and younger adults with visual motion cues (i.e., optic flow) and systematically manipulated the presence or absence of congruent auditory cues to self-motion (i.e., engine, tire, and wind sounds). Results demonstrated that the presence or absence of congruent auditory input had different effects on older and younger adults. Both age groups demonstrated a reduction in speed variability when auditory cues were present compared to when they were absent, but older adults demonstrated a proportionally greater reduction in speed variability under combined sensory conditions. These results are consistent with evidence indicating that multisensory integration is heightened in older adults. Importantly, this study is the first to provide evidence to suggest that age differences in multisensory integration may generalize from simple stimulus detection tasks to the integration of the more complex and dynamic visual and auditory cues that are experienced during self-motion. PMID:27199829

Learning Grammatical Categories from Distributional Cues: Flexible Frames for Language Acquisition

ERIC Educational Resources Information Center

St. Clair, Michelle C.; Monaghan, Padraic; Christiansen, Morten H.

2010-01-01

Numerous distributional cues in the child's environment may potentially assist in language learning, but what cues are useful to the child and when are these cues utilised? We propose that the most useful source of distributional cue is a flexible frame surrounding the word, where the language learner integrates information from the preceding and…

Combining path integration and remembered landmarks when navigating without vision.

PubMed

Kalia, Amy A; Schrater, Paul R; Legge, Gordon E

2013-01-01

This study investigated the interaction between remembered landmark and path integration strategies for estimating current location when walking in an environment without vision. We asked whether observers navigating without vision only rely on path integration information to judge their location, or whether remembered landmarks also influence judgments. Participants estimated their location in a hallway after viewing a target (remembered landmark cue) and then walking blindfolded to the same or a conflicting location (path integration cue). We found that participants averaged remembered landmark and path integration information when they judged that both sources provided congruent information about location, which resulted in more precise estimates compared to estimates made with only path integration. In conclusion, humans integrate remembered landmarks and path integration in a gated fashion, dependent on the congruency of the information. Humans can flexibly combine information about remembered landmarks with path integration cues while navigating without visual information.

Combining Path Integration and Remembered Landmarks When Navigating without Vision

PubMed Central

Kalia, Amy A.; Schrater, Paul R.; Legge, Gordon E.

2013-01-01

This study investigated the interaction between remembered landmark and path integration strategies for estimating current location when walking in an environment without vision. We asked whether observers navigating without vision only rely on path integration information to judge their location, or whether remembered landmarks also influence judgments. Participants estimated their location in a hallway after viewing a target (remembered landmark cue) and then walking blindfolded to the same or a conflicting location (path integration cue). We found that participants averaged remembered landmark and path integration information when they judged that both sources provided congruent information about location, which resulted in more precise estimates compared to estimates made with only path integration. In conclusion, humans integrate remembered landmarks and path integration in a gated fashion, dependent on the congruency of the information. Humans can flexibly combine information about remembered landmarks with path integration cues while navigating without visual information. PMID:24039742

Integration of Pragmatic and Phonetic Cues in Spoken Word Recognition

PubMed Central

Rohde, Hannah; Ettlinger, Marc

2015-01-01

Although previous research has established that multiple top-down factors guide the identification of words during speech processing, the ultimate range of information sources that listeners integrate from different levels of linguistic structure is still unknown. In a set of experiments, we investigate whether comprehenders can integrate information from the two most disparate domains: pragmatic inference and phonetic perception. Using contexts that trigger pragmatic expectations regarding upcoming coreference (expectations for either he or she), we test listeners' identification of phonetic category boundaries (using acoustically ambiguous words on the/hi/∼/∫i/continuum). The results indicate that, in addition to phonetic cues, word recognition also reflects pragmatic inference. These findings are consistent with evidence for top-down contextual effects from lexical, syntactic, and semantic cues, but they extend this previous work by testing cues at the pragmatic level and by eliminating a statistical-frequency confound that might otherwise explain the previously reported results. We conclude by exploring the time-course of this interaction and discussing how different models of cue integration could be adapted to account for our results. PMID:22250908

Integration of length and curvature in haptic perception.

PubMed

Panday, Virjanand; Tiest, Wouter M Bergmann; Kappers, Astrid M L

2014-01-24

We investigated if and how length and curvature information are integrated when an object is explored in one hand. Subjects were asked to explore four types of objects between thumb and index finger. Objects differed in either length, curvature, both length and curvature correlated as in a circle, or anti-correlated. We found that when both length and curvature are present, performance is significantly better than when only one of the two cues is available. Therefore, we conclude that there is integration of length and curvature. Moreover, if the two cues are correlated in a circular cross-section instead of in an anti-correlated way, performance is better than predicted by a combination of two independent cues. We conclude that integration of curvature and length is highly efficient when the cues in the object are combined as in a circle, which is the most common combination of curvature and length in daily life.

Spectro-temporal cues enhance modulation sensitivity in cochlear implant users.

PubMed

Zheng, Yi; Escabí, Monty; Litovsky, Ruth Y

2017-08-01

Although speech understanding is highly variable amongst cochlear implants (CIs) subjects, the remarkably high speech recognition performance of many CI users is unexpected and not well understood. Numerous factors, including neural health and degradation of the spectral information in the speech signal of CIs, likely contribute to speech understanding. We studied the ability to use spectro-temporal modulations, which may be critical for speech understanding and discrimination, and hypothesize that CI users adopt a different perceptual strategy than normal-hearing (NH) individuals, whereby they rely more heavily on joint spectro-temporal cues to enhance detection of auditory cues. Modulation detection sensitivity was studied in CI users and NH subjects using broadband "ripple" stimuli that were modulated spectrally, temporally, or jointly, i.e., spectro-temporally. The spectro-temporal modulation transfer functions of CI users and NH subjects was decomposed into spectral and temporal dimensions and compared to those subjects' spectral-only and temporal-only modulation transfer functions. In CI users, the joint spectro-temporal sensitivity was better than that predicted by spectral-only and temporal-only sensitivity, indicating a heightened spectro-temporal sensitivity. Such an enhancement through the combined integration of spectral and temporal cues was not observed in NH subjects. The unique use of spectro-temporal cues by CI patients can yield benefits for use of cues that are important for speech understanding. This finding has implications for developing sound processing strategies that may rely on joint spectro-temporal modulations to improve speech comprehension of CI users, and the findings of this study may be valuable for developing clinical assessment tools to optimize CI processor performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Information Integration in Multiple Cue Judgment: A Division of Labor Hypothesis

ERIC Educational Resources Information Center

Juslin, Peter; Karlsson, Linnea; Olsson, Henrik

2008-01-01

There is considerable evidence that judgment is constrained to additive integration of information. The authors propose an explanation of why serial and additive cognitive integration can produce accurate multiple cue judgment both in additive and non-additive environments in terms of an adaptive division of labor between multiple representations.…

The Integration of Occlusion and Disparity Information for Judging Depth in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Smith, Danielle; Ropar, Danielle; Allen, Harriet A.

2017-01-01

In autism spectrum disorder (ASD), atypical integration of visual depth cues may be due to flattened perceptual priors or selective fusion. The current study attempts to disentangle these explanations by psychophysically assessing within-modality integration of ordinal (occlusion) and metric (disparity) depth cues while accounting for sensitivity…

Evidence for cue-independent spatial representation in the human auditory cortex during active listening

PubMed Central

McLaughlin, Susan A.; Rinne, Teemu; Stecker, G. Christopher

2017-01-01

Few auditory functions are as important or as universal as the capacity for auditory spatial awareness (e.g., sound localization). That ability relies on sensitivity to acoustical cues—particularly interaural time and level differences (ITD and ILD)—that correlate with sound-source locations. Under nonspatial listening conditions, cortical sensitivity to ITD and ILD takes the form of broad contralaterally dominated response functions. It is unknown, however, whether that sensitivity reflects representations of the specific physical cues or a higher-order representation of auditory space (i.e., integrated cue processing), nor is it known whether responses to spatial cues are modulated by active spatial listening. To investigate, sensitivity to parametrically varied ITD or ILD cues was measured using fMRI during spatial and nonspatial listening tasks. Task type varied across blocks where targets were presented in one of three dimensions: auditory location, pitch, or visual brightness. Task effects were localized primarily to lateral posterior superior temporal gyrus (pSTG) and modulated binaural-cue response functions differently in the two hemispheres. Active spatial listening (location tasks) enhanced both contralateral and ipsilateral responses in the right hemisphere but maintained or enhanced contralateral dominance in the left hemisphere. Two observations suggest integrated processing of ITD and ILD. First, overlapping regions in medial pSTG exhibited significant sensitivity to both cues. Second, successful classification of multivoxel patterns was observed for both cue types and—critically—for cross-cue classification. Together, these results suggest a higher-order representation of auditory space in the human auditory cortex that at least partly integrates the specific underlying cues. PMID:28827357

Experience-Dependency of Reliance on Local Visual and Idiothetic Cues for Spatial Representations Created in the Absence of Distal Information.

PubMed

Draht, Fabian; Zhang, Sijie; Rayan, Abdelrahman; Schönfeld, Fabian; Wiskott, Laurenz; Manahan-Vaughan, Denise

2017-01-01

Spatial encoding in the hippocampus is based on a range of different input sources. To generate spatial representations, reliable sensory cues from the external environment are integrated with idiothetic cues, derived from self-movement, that enable path integration and directional perception. In this study, we examined to what extent idiothetic cues significantly contribute to spatial representations and navigation: we recorded place cells while rodents navigated towards two visually identical chambers in 180° orientation via two different paths in darkness and in the absence of reliable auditory or olfactory cues. Our goal was to generate a conflict between local visual and direction-specific information, and then to assess which strategy was prioritized in different learning phases. We observed that, in the absence of distal cues, place fields are initially controlled by local visual cues that override idiothetic cues, but that with multiple exposures to the paradigm, spaced at intervals of days, idiothetic cues become increasingly implemented in generating an accurate spatial representation. Taken together, these data support that, in the absence of distal cues, local visual cues are prioritized in the generation of context-specific spatial representations through place cells, whereby idiothetic cues are deemed unreliable. With cumulative exposures to the environments, the animal learns to attend to subtle idiothetic cues to resolve the conflict between visual and direction-specific information.

Experience-Dependency of Reliance on Local Visual and Idiothetic Cues for Spatial Representations Created in the Absence of Distal Information

PubMed Central

Draht, Fabian; Zhang, Sijie; Rayan, Abdelrahman; Schönfeld, Fabian; Wiskott, Laurenz; Manahan-Vaughan, Denise

2017-01-01

Spatial encoding in the hippocampus is based on a range of different input sources. To generate spatial representations, reliable sensory cues from the external environment are integrated with idiothetic cues, derived from self-movement, that enable path integration and directional perception. In this study, we examined to what extent idiothetic cues significantly contribute to spatial representations and navigation: we recorded place cells while rodents navigated towards two visually identical chambers in 180° orientation via two different paths in darkness and in the absence of reliable auditory or olfactory cues. Our goal was to generate a conflict between local visual and direction-specific information, and then to assess which strategy was prioritized in different learning phases. We observed that, in the absence of distal cues, place fields are initially controlled by local visual cues that override idiothetic cues, but that with multiple exposures to the paradigm, spaced at intervals of days, idiothetic cues become increasingly implemented in generating an accurate spatial representation. Taken together, these data support that, in the absence of distal cues, local visual cues are prioritized in the generation of context-specific spatial representations through place cells, whereby idiothetic cues are deemed unreliable. With cumulative exposures to the environments, the animal learns to attend to subtle idiothetic cues to resolve the conflict between visual and direction-specific information. PMID:28634444

Motion Cueing Algorithm Development: Piloted Performance Testing of the Cueing Algorithms

NASA Technical Reports Server (NTRS)

Houck, Jacob A. (Technical Monitor); Telban, Robert J.; Cardullo, Frank M.; Kelly, Lon C.

2005-01-01

The relative effectiveness in simulating aircraft maneuvers with both current and newly developed motion cueing algorithms was assessed with an eleven-subject piloted performance evaluation conducted on the NASA Langley Visual Motion Simulator (VMS). In addition to the current NASA adaptive algorithm, two new cueing algorithms were evaluated: the optimal algorithm and the nonlinear algorithm. The test maneuvers included a straight-in approach with a rotating wind vector, an offset approach with severe turbulence and an on/off lateral gust that occurs as the aircraft approaches the runway threshold, and a takeoff both with and without engine failure after liftoff. The maneuvers were executed with each cueing algorithm with added visual display delay conditions ranging from zero to 200 msec. Two methods, the quasi-objective NASA Task Load Index (TLX), and power spectral density analysis of pilot control, were used to assess pilot workload. Piloted performance parameters for the approach maneuvers, the vertical velocity upon touchdown and the runway touchdown position, were also analyzed but did not show any noticeable difference among the cueing algorithms. TLX analysis reveals, in most cases, less workload and variation among pilots with the nonlinear algorithm. Control input analysis shows pilot-induced oscillations on a straight-in approach were less prevalent compared to the optimal algorithm. The augmented turbulence cues increased workload on an offset approach that the pilots deemed more realistic compared to the NASA adaptive algorithm. The takeoff with engine failure showed the least roll activity for the nonlinear algorithm, with the least rudder pedal activity for the optimal algorithm.

Gravity dependence of the effect of optokinetic stimulation on the subjective visual vertical.

PubMed

Ward, Bryan K; Bockisch, Christopher J; Caramia, Nicoletta; Bertolini, Giovanni; Tarnutzer, Alexander Andrea

2017-05-01

Accurate and precise estimates of direction of gravity are essential for spatial orientation. According to Bayesian theory, multisensory vestibular, visual, and proprioceptive input is centrally integrated in a weighted fashion based on the reliability of the component sensory signals. For otolithic input, a decreasing signal-to-noise ratio was demonstrated with increasing roll angle. We hypothesized that the weights of vestibular (otolithic) and extravestibular (visual/proprioceptive) sensors are roll-angle dependent and predicted an increased weight of extravestibular cues with increasing roll angle, potentially following the Bayesian hypothesis. To probe this concept, the subjective visual vertical (SVV) was assessed in different roll positions (≤ ± 120°, steps = 30°, n = 10) with/without presenting an optokinetic stimulus (velocity = ± 60°/s). The optokinetic stimulus biased the SVV toward the direction of stimulus rotation for roll angles ≥ ± 30° ( P < 0.005). Offsets grew from 3.9 ± 1.8° (upright) to 22.1 ± 11.8° (±120° roll tilt, P < 0.001). Trial-to-trial variability increased with roll angle, demonstrating a nonsignificant increase when providing optokinetic stimulation. Variability and optokinetic bias were correlated ( R 2 = 0.71, slope = 0.71, 95% confidence interval = 0.57-0.86). An optimal-observer model combining an optokinetic bias with vestibular input reproduced measured errors closely. These findings support the hypothesis of a weighted multisensory integration when estimating direction of gravity with optokinetic stimulation. Visual input was weighted more when vestibular input became less reliable, i.e., at larger roll-tilt angles. However, according to Bayesian theory, the variability of combined cues is always lower than the variability of each source cue. If the observed increase in variability, although nonsignificant, is true, either it must depend on an additional source of variability, added after SVV computation, or it would conflict with the Bayesian hypothesis. NEW & NOTEWORTHY Applying a rotating optokinetic stimulus while recording the subjective visual vertical in different whole body roll angles, we noted the optokinetic-induced bias to correlate with the roll angle. These findings allow the hypothesis that the established optimal weighting of single-sensory cues depending on their reliability to estimate direction of gravity could be extended to a bias caused by visual self-motion stimuli. Copyright © 2017 the American Physiological Society.

Vibrotactile Discrimination in the Rat Whisker System is Based on Neuronal Coding of Instantaneous Kinematic Cues

PubMed Central

Waiblinger, Christian; Brugger, Dominik; Schwarz, Cornelius

2015-01-01

Which physical parameter of vibrissa deflections is extracted by the rodent tactile system for discrimination? Particularly, it remains unclear whether perception has access to instantaneous kinematic parameters (i.e., the details of the trajectory) or relies on temporally integration of the movement trajectory such as frequency (e.g., spectral information) and intensity (e.g., mean speed). Here, we use a novel detection of change paradigm in head-fixed rats, which presents pulsatile vibrissa stimuli in seamless sequence for discrimination. This procedure ensures that processes of decision making can directly tap into sensory signals (no memory functions involved). We find that discrimination performance based on instantaneous kinematic cues far exceeds the ones provided by frequency and intensity. Neuronal modeling based on barrel cortex single units shows that small populations of sensitive neurons provide a transient signal that optimally fits the characteristic of the subject's perception. The present study is the first to show that perceptual read-out is superior in situations allowing the subject to base perception on detailed trajectory cues, that is, instantaneous kinematic variables. A possible impact of this finding on tactile systems of other species is suggested by evidence for instantaneous coding also in primates. PMID:24169940

Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy-covariance, biometric and continuous soil chamber measurements

NASA Astrophysics Data System (ADS)

Zanotelli, D.; Montagnani, L.; Manca, G.; Tagliavini, M.

2012-10-01

Carbon use efficiency (CUE) is a functional parameter that could possibly link the current increasingly accurate global estimates of gross primary production with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, net primary production (NPP) and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a~measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross-check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard both net ecosystem production and gross primary production on yearly basis, 380 ± 30 g C m-2 and 1263 ± 189 g C m-2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruits: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.09, was higher than the previously suggested constant values of 0.47-0.50. Low nitrogen investment in fruits, the limited root-apparatus, and the optimal growth temperature and nutritional condition observed at the site are suggested to be explanatory variables for the high CUE observed.

Role of Cigarette Sensory Cues in Modifying Puffing Topography

PubMed Central

Rees, Vaughan W.; Kreslake, Jennifer M.; Wayne, Geoffrey Ferris; O Connor, Richard J.; Cummings, K. Michael; Connolly, Gregory N.

2012-01-01

Background Human puffing topography promotes tobacco dependence by ensuring nicotine delivery, but the factors that determine puffing behavior are not well explained by existing models. Chemosensory cues generated by variations in cigarette product design features may serve as conditioned cues to allow the smoker to optimize nicotine delivery by adjusting puffing topography. Internal tobacco industry research documents were reviewed to understand the influence of sensory cues on puffing topography, and to examine how the tobacco industry has designed cigarettes, including modified risk tobacco products (MRTPs), to enhance puffing behavior to optimize nicotine delivery and product acceptability. Methods Relevant internal tobacco industry documents were identified using systematic searching with key search terms and phrases, and then snowball sampling method was applied to establish further search terms. Results Modern cigarettes are designed by cigarette manufacturers to provide sensory characteristics that not only maintain appeal, but provide cues which inform puffing intensity. Alterations in the chemosensory cues provided in tobacco smoke play an important role in modifying smoking behavior independently of the central effects of nicotine. Conclusions An associative learning model is proposed to explain the influence of chemosensory cues on variation in puffing topography. These cues are delivered via tobacco smoke and are moderated by design features and additives used in cigarettes. The implications for regulation of design features of modified risk tobacco products, which may act to promote intensive puffing while lowering risk perceptions, are discussed. PMID:22365895

Optimal switching between geocentric and egocentric strategies in navigation

PubMed Central

Mahadevan, L.

2016-01-01

Animals use a combination of egocentric navigation driven by the internal integration of environmental cues, interspersed with geocentric course correction and reorientation. These processes are accompanied by uncertainty in sensory acquisition of information, planning and execution. Inspired by observations of dung beetle navigational strategies that show switching between geocentric and egocentric strategies, we consider the question of optimal reorientation rates for the navigation of an agent moving along a preferred direction in the presence of multiple sources of noise. We address this using a model that takes the form of a correlated random walk at short time scales that is punctuated by reorientation events leading to a biased random walks at long time scales. This allows us to identify optimal alternation schemes and characterize their robustness in the context of noisy sensory acquisition as well as performance errors linked with variations in environmental conditions and agent–environment interactions. PMID:27493769

Weighting of Acoustic Cues to a Manner Distinction by Children With and Without Hearing Loss

PubMed Central

Lowenstein, Joanna H.

2015-01-01

Purpose Children must develop optimal perceptual weighting strategies for processing speech in their first language. Hearing loss can interfere with that development, especially if cochlear implants are required. The three goals of this study were to measure, for children with and without hearing loss: (a) cue weighting for a manner distinction, (b) sensitivity to those cues, and (c) real-world communication functions. Method One hundred and seven children (43 with normal hearing [NH], 17 with hearing aids [HAs], and 47 with cochlear implants [CIs]) performed several tasks: labeling of stimuli from /bɑ/-to-/wɑ/ continua varying in formant and amplitude rise time (FRT and ART), discrimination of ART, word recognition, and phonemic awareness. Results Children with hearing loss were less attentive overall to acoustic structure than children with NH. Children with CIs, but not those with HAs, weighted FRT less and ART more than children with NH. Sensitivity could not explain cue weighting. FRT cue weighting explained significant amounts of variability in word recognition and phonemic awareness; ART cue weighting did not. Conclusion Signal degradation inhibits access to spectral structure for children with CIs, but cannot explain their delayed development of optimal weighting strategies. Auditory training could strengthen the weighting of spectral cues for children with CIs, thus aiding spoken language acquisition. PMID:25813201

Effectiveness of self-generated cues in early Alzheimer's disease.

PubMed

Lipinska, B; Bäckman, L; Mäntylä, T; Viitanen, M

1994-12-01

The ability to utilize cognitive support in the form of self-generated cues in mild Alzheimer's disease (AD), and the factors promoting efficient cue utilization in this group of patients, were examined in two experiments on memory for words. Results from both experiments showed that normal old adults as well as AD patients performed better with self-generated cues than with experimenter-provided cues, although the latter type of cues resulted in gains relative to free recall. The findings indicate no qualitative differences in patterns of performance between the normal old and the AD patients. For both groups of subjects, cue effectiveness was optimized when (a) there was self-generation activity at encoding, and (b) encoding and retrieval conditions were compatible.

Integrated, systems metabolic picture of acetone-butanol-ethanol fermentation by Clostridium acetobutylicum.

PubMed

Liao, Chen; Seo, Seung-Oh; Celik, Venhar; Liu, Huaiwei; Kong, Wentao; Wang, Yi; Blaschek, Hans; Jin, Yong-Su; Lu, Ting

2015-07-07

Microbial metabolism involves complex, system-level processes implemented via the orchestration of metabolic reactions, gene regulation, and environmental cues. One canonical example of such processes is acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum, during which cells convert carbon sources to organic acids that are later reassimilated to produce solvents as a strategy for cellular survival. The complexity and systems nature of the process have been largely underappreciated, rendering challenges in understanding and optimizing solvent production. Here, we present a system-level computational framework for ABE fermentation that combines metabolic reactions, gene regulation, and environmental cues. We developed the framework by decomposing the entire system into three modules, building each module separately, and then assembling them back into an integrated system. During the model construction, a bottom-up approach was used to link molecular events at the single-cell level into the events at the population level. The integrated model was able to successfully reproduce ABE fermentations of the WT C. acetobutylicum (ATCC 824), as well as its mutants, using data obtained from our own experiments and from literature. Furthermore, the model confers successful predictions of the fermentations with various network perturbations across metabolic, genetic, and environmental aspects. From foundation to applications, the framework advances our understanding of complex clostridial metabolism and physiology and also facilitates the development of systems engineering strategies for the production of advanced biofuels.

Integrated, systems metabolic picture of acetone-butanol-ethanol fermentation by Clostridium acetobutylicum

PubMed Central

Liao, Chen; Seo, Seung-Oh; Celik, Venhar; Liu, Huaiwei; Kong, Wentao; Wang, Yi; Blaschek, Hans; Jin, Yong-Su; Lu, Ting

2015-01-01

Microbial metabolism involves complex, system-level processes implemented via the orchestration of metabolic reactions, gene regulation, and environmental cues. One canonical example of such processes is acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum, during which cells convert carbon sources to organic acids that are later reassimilated to produce solvents as a strategy for cellular survival. The complexity and systems nature of the process have been largely underappreciated, rendering challenges in understanding and optimizing solvent production. Here, we present a system-level computational framework for ABE fermentation that combines metabolic reactions, gene regulation, and environmental cues. We developed the framework by decomposing the entire system into three modules, building each module separately, and then assembling them back into an integrated system. During the model construction, a bottom-up approach was used to link molecular events at the single-cell level into the events at the population level. The integrated model was able to successfully reproduce ABE fermentations of the WT C. acetobutylicum (ATCC 824), as well as its mutants, using data obtained from our own experiments and from literature. Furthermore, the model confers successful predictions of the fermentations with various network perturbations across metabolic, genetic, and environmental aspects. From foundation to applications, the framework advances our understanding of complex clostridial metabolism and physiology and also facilitates the development of systems engineering strategies for the production of advanced biofuels. PMID:26100881

A comparison of visuomotor cue integration strategies for object placement and prehension.

PubMed

Greenwald, Hal S; Knill, David C

2009-01-01

Visual cue integration strategies are known to depend on cue reliability and how rapidly the visual system processes incoming information. We investigated whether these strategies also depend on differences in the information demands for different natural tasks. Using two common goal-oriented tasks, prehension and object placement, we determined whether monocular and binocular information influence estimates of three-dimensional (3D) orientation differently depending on task demands. Both tasks rely on accurate 3D orientation estimates, but 3D position is potentially more important for grasping. Subjects placed an object on or picked up a disc in a virtual environment. On some trials, the monocular cues (aspect ratio and texture compression) and binocular cues (e.g., binocular disparity) suggested slightly different 3D orientations for the disc; these conflicts either were present upon initial stimulus presentation or were introduced after movement initiation, which allowed us to quantify how information from the cues accumulated over time. We analyzed the time-varying orientations of subjects' fingers in the grasping task and those of the object in the object placement task to quantify how different visual cues influenced motor control. In the first experiment, different subjects performed each task, and those performing the grasping task relied on binocular information more when orienting their hands than those performing the object placement task. When subjects in the second experiment performed both tasks in interleaved sessions, binocular cues were still more influential during grasping than object placement, and the different cue integration strategies observed for each task in isolation were maintained. In both experiments, the temporal analyses showed that subjects processed binocular information faster than monocular information, but task demands did not affect the time course of cue processing. How one uses visual cues for motor control depends on the task being performed, although how quickly the information is processed appears to be task invariant.

Common region wins the competition between extrinsic grouping cues: Evidence from a task without explicit attention to grouping.

PubMed

Montoro, Pedro R; Villalba-García, Cristina; Luna, Dolores; Hinojosa, José A

2017-12-01

The competition between perceptual grouping factors is a relatively ignored topic, especially in the case of extrinsic grouping cues (e.g., common region or connectedness). Recent studies have examined the integration of extrinsic cues using tasks that induce selective attention to groups based on different grouping cues. However, this procedure could generate alternative strategies for task performance, which are non-related to the perceptual grouping operations. In the current work, we used an indirect task, i.e. repetition discrimination task, without explicit attention to grouping cues to further examine the rules that govern dominance between competing extrinsic grouping factors. This procedure allowed us to obtain an unbiased measure of the competition between common region and connectedness cues acting within the same display. The results corroborate previous data showing that grouping by common region dominated the perceived organization of the display, even though the phenomenological strength of the grouping cues was equated for each participant by means of a preliminary scaling task. Our results highlight the relevance of using indirect tasks as an essential tool for the systematic study of the integration of extrinsic grouping cues.

Vector navigation in desert ants, Cataglyphis fortis: celestial compass cues are essential for the proper use of distance information.

PubMed

Sommer, Stefan; Wehner, Rüdiger

2005-10-01

Foraging desert ants navigate primarily by path integration. They continually update homing direction and distance by employing a celestial compass and an odometer. Here we address the question of whether information about travel distance is correctly used in the absence of directional information. By using linear channels that were partly covered to exclude celestial compass cues, we were able to test the distance component of the path-integration process while suppressing the directional information. Our results suggest that the path integrator cannot process the distance information accumulated by the odometer while ants are deprived of celestial compass information. Hence, during path integration directional cues are a prerequisite for the proper use of travel-distance information by ants.

Bayesian integration of position and orientation cues in perception of biological and non-biological forms.

PubMed

Thurman, Steven M; Lu, Hongjing

2014-01-01

Visual form analysis is fundamental to shape perception and likely plays a central role in perception of more complex dynamic shapes, such as moving objects or biological motion. Two primary form-based cues serve to represent the overall shape of an object: the spatial position and the orientation of locations along the boundary of the object. However, it is unclear how the visual system integrates these two sources of information in dynamic form analysis, and in particular how the brain resolves ambiguities due to sensory uncertainty and/or cue conflict. In the current study, we created animations of sparsely-sampled dynamic objects (human walkers or rotating squares) comprised of oriented Gabor patches in which orientation could either coincide or conflict with information provided by position cues. When the cues were incongruent, we found a characteristic trade-off between position and orientation information whereby position cues increasingly dominated perception as the relative uncertainty of orientation increased and vice versa. Furthermore, we found no evidence for differences in the visual processing of biological and non-biological objects, casting doubt on the claim that biological motion may be specialized in the human brain, at least in specific terms of form analysis. To explain these behavioral results quantitatively, we adopt a probabilistic template-matching model that uses Bayesian inference within local modules to estimate object shape separately from either spatial position or orientation signals. The outputs of the two modules are integrated with weights that reflect individual estimates of subjective cue reliability, and integrated over time to produce a decision about the perceived dynamics of the input data. Results of this model provided a close fit to the behavioral data, suggesting a mechanism in the human visual system that approximates rational Bayesian inference to integrate position and orientation signals in dynamic form analysis.

Multisensory Integration of Visual and Vestibular Signals Improves Heading Discrimination in the Presence of a Moving Object

PubMed Central

Dokka, Kalpana; DeAngelis, Gregory C.

2015-01-01

Humans and animals are fairly accurate in judging their direction of self-motion (i.e., heading) from optic flow when moving through a stationary environment. However, an object moving independently in the world alters the optic flow field and may bias heading perception if the visual system cannot dissociate object motion from self-motion. We investigated whether adding vestibular self-motion signals to optic flow enhances the accuracy of heading judgments in the presence of a moving object. Macaque monkeys were trained to report their heading (leftward or rightward relative to straight-forward) when self-motion was specified by vestibular, visual, or combined visual-vestibular signals, while viewing a display in which an object moved independently in the (virtual) world. The moving object induced significant biases in perceived heading when self-motion was signaled by either visual or vestibular cues alone. However, this bias was greatly reduced when visual and vestibular cues together signaled self-motion. In addition, multisensory heading discrimination thresholds measured in the presence of a moving object were largely consistent with the predictions of an optimal cue integration strategy. These findings demonstrate that multisensory cues facilitate the perceptual dissociation of self-motion and object motion, consistent with computational work that suggests that an appropriate decoding of multisensory visual-vestibular neurons can estimate heading while discounting the effects of object motion. SIGNIFICANCE STATEMENT Objects that move independently in the world alter the optic flow field and can induce errors in perceiving the direction of self-motion (heading). We show that adding vestibular (inertial) self-motion signals to optic flow almost completely eliminates the errors in perceived heading induced by an independently moving object. Furthermore, this increased accuracy occurs without a substantial loss in the precision. Our results thus demonstrate that vestibular signals play a critical role in dissociating self-motion from object motion. PMID:26446214

Integrated action of pheromone signals in promoting courtship behavior in male mice

PubMed Central

Haga-Yamanaka, Sachiko; Ma, Limei; He, Jie; Qiu, Qiang; Lavis, Luke D; Looger, Loren L; Yu, C Ron

2014-01-01

The mammalian vomeronasal organ encodes pheromone information about gender, reproductive status, genetic background and individual differences. It remains unknown how pheromone information interacts to trigger innate behaviors. In this study, we identify vomeronasal receptors responsible for detecting female pheromones. A sub-group of V1re clade members recognizes gender-identifying cues in female urine. Multiple members of the V1rj clade are cognate receptors for urinary estrus signals, as well as for sulfated estrogen (SE) compounds. In both cases, the same cue activates multiple homologous receptors, suggesting redundancy in encoding female pheromone cues. Neither gender-specific cues nor SEs alone are sufficient to promote courtship behavior in male mice, whereas robust courtship behavior can be induced when the two cues are applied together. Thus, integrated action of different female cues is required in pheromone-triggered mating behavior. These results suggest a gating mechanism in the vomeronasal circuit in promoting specific innate behavior. DOI: http://dx.doi.org/10.7554/eLife.03025.001 PMID:25073926

Organization principles in visual working memory: Evidence from sequential stimulus display.

PubMed

Gao, Zaifeng; Gao, Qiyang; Tang, Ning; Shui, Rende; Shen, Mowei

2016-01-01

Although the mechanisms of visual working memory (VWM) have been studied extensively in recent years, the active property of VWM has received less attention. In the current study, we examined how VWM integrates sequentially presented stimuli by focusing on the role of Gestalt principles, which are important organizing principles in perceptual integration. We manipulated the level of Gestalt cues among three or four sequentially presented objects that were memorized. The Gestalt principle could not emerge unless all the objects appeared together. We distinguished two hypotheses: a perception-alike hypothesis and an encoding-specificity hypothesis. The former predicts that the Gestalt cue will play a role in information integration within VWM; the latter predicts that the Gestalt cue will not operate within VWM. In four experiments, we demonstrated that collinearity (Experiment 1) and closure (Experiment 2) cues significantly improved VWM performance, and this facilitation was not affected by the testing manner (Experiment 3) or by adding extra colors to the memorized objects (Experiment 4). Finally, we re-established the Gestalt cue benefit with similarity cues (Experiment 5). These findings together suggest that VWM realizes and uses potential Gestalt principles within the stored representations, supporting a perception-alike hypothesis. Copyright © 2015 Elsevier B.V. All rights reserved.

Reinforcement Probability Modulates Temporal Memory Selection and Integration Processes

PubMed Central

Matell, Matthew S.; Kurti, Allison N.

2013-01-01

We have previously shown that rats trained in a mixed-interval peak procedure (tone = 4s, light = 12s) respond in a scalar manner at a time in between the trained peak times when presented with the stimulus compound (Swanton & Matell, 2011). In our previous work, the two component cues were reinforced with different probabilities (short = 20%, long = 80%) to equate response rates, and we found that the compound peak time was biased toward the cue with the higher reinforcement probability. Here, we examined the influence that different reinforcement probabilities have on the temporal location and shape of the compound response function. We found that the time of peak responding shifted as a function of the relative reinforcement probability of the component cues, becoming earlier as the relative likelihood of reinforcement associated with the short cue increased. However, as the relative probabilities of the component cues grew dissimilar, the compound peak became non-scalar, suggesting that the temporal control of behavior shifted from a process of integration to one of selection. As our previous work has utilized durations and reinforcement probabilities more discrepant than those used here, these data suggest that the processes underlying the integration/selection decision for time are based on cue value. PMID:23896560

All Cues Are Not Created Equal: The Case for Facilitating the Acquisition of Typical Weighting Strategies in Children with Hearing Loss

ERIC Educational Resources Information Center

Lowenstein, Joanna H.; Nittrouer, Susan

2015-01-01

Purpose: One task of childhood involves learning to optimally weight acoustic cues in the speech signal in order to recover phonemic categories. This study examined the extent to which spectral degradation, as associated with cochlear implants, might interfere. The 3 goals were to measure, for adults and children, (a) cue weighting with spectrally…

Contribution of intravestibular sensory conflict to motion sickness and dizziness in migraine disorders.

PubMed

Wang, Joanne; Lewis, Richard F

2016-10-01

Migraine is associated with enhanced motion sickness susceptibility and can cause episodic vertigo [vestibular migraine (VM)], but the mechanisms relating migraine to these vestibular symptoms remain uncertain. We tested the hypothesis that the central integration of rotational cues (from the semicircular canals) and gravitational cues (from the otolith organs) is abnormal in migraine patients. A postrotational tilt paradigm generated a conflict between canal cues (which indicate the head is rotating) and otolith cues (which indicate the head is tilted and stationary), and eye movements were measured to quantify two behaviors that are thought to minimize this conflict: suppression and reorientation of the central angular velocity signal, evidenced by attenuation ("dumping") of the vestibuloocular reflex and shifting of the rotational axis of the vestibuloocular reflex toward the earth vertical. We found that normal and migraine subjects, but not VM patients, displayed an inverse correlation between the extent of dumping and the size of the axis shift such that the net "conflict resolution" mediated through these two mechanisms approached an optimal value and that the residual sensory conflict in VM patients (but not migraine or normal subjects) correlated with motion sickness susceptibility. Our findings suggest that the brain normally controls the dynamic and spatial characteristics of central vestibular signals to minimize intravestibular sensory conflict and that this process is disrupted in VM, which may be responsible for the enhance motion intolerance and episodic vertigo that characterize this disorder. Copyright © 2016 the American Physiological Society.

Transcriptional integration of mitogenic and mechanical signals by Myc and YAP

PubMed Central

Croci, Ottavio; De Fazio, Serena; Biagioni, Francesca; Donato, Elisa; Caganova, Marieta; Curti, Laura; Doni, Mirko; Sberna, Silvia; Aldeghi, Deborah; Biancotto, Chiara; Verrecchia, Alessandro; Olivero, Daniela; Amati, Bruno

2017-01-01

Mammalian cells must integrate environmental cues to determine coherent physiological responses. The transcription factors Myc and YAP–TEAD act downstream from mitogenic signals, with the latter responding also to mechanical cues. Here, we show that these factors coordinately regulate genes required for cell proliferation. Activation of Myc led to extensive association with its genomic targets, most of which were prebound by TEAD. At these loci, recruitment of YAP was Myc-dependent and led to full transcriptional activation. This cooperation was critical for cell cycle entry, organ growth, and tumorigenesis. Thus, Myc and YAP–TEAD integrate mitogenic and mechanical cues at the transcriptional level to provide multifactorial control of cell proliferation. PMID:29141911

Incidence of vertical phoria on postural control during binocular vision: what perspective for prevention to nonspecific chronic pain management?

PubMed

Matheron, Eric; Kapoula, Zoï

2015-01-01

Vertical heterophoria (VH) is the latent vertical misalignment of the eyes when the retinal images are dissociated, vertical orthophoria (VO) when there is no misalignment. Studies on postural control, during binocular vision in upright stance, reported that healthy subjects with small VH vs. VO are less stable, but the experimental cancellation of VH with an appropriate prism improves postural stability. The same behavior was recorded in nonspecific chronic back pain subjects, all with VH. It was hypothesized that, without refraction problems, VH indicates a perturbation of the somaesthetic cues required in the sensorimotor loops involved in postural control and the capacity of the CNS to optimally integrate these cues, suggesting prevention possibilities. Sensorimotor conflict can induce pain and modify sensory perception in some healthy subjects; some nonspecific pain or chronic pain could result from such prolonged conflict in which VH could be a sign, with new theoretical and clinical implications.

Comparison of simulator fidelity model predictions with in-simulator evaluation data

NASA Technical Reports Server (NTRS)

Parrish, R. V.; Mckissick, B. T.; Ashworth, B. R.

1983-01-01

A full factorial in simulator experiment of a single axis, multiloop, compensatory pitch tracking task is described. The experiment was conducted to provide data to validate extensions to an analytic, closed loop model of a real time digital simulation facility. The results of the experiment encompassing various simulation fidelity factors, such as visual delay, digital integration algorithms, computer iteration rates, control loading bandwidths and proprioceptive cues, and g-seat kinesthetic cues, are compared with predictions obtained from the analytic model incorporating an optimal control model of the human pilot. The in-simulator results demonstrate more sensitivity to the g-seat and to the control loader conditions than were predicted by the model. However, the model predictions are generally upheld, although the predicted magnitudes of the states and of the error terms are sometimes off considerably. Of particular concern is the large sensitivity difference for one control loader condition, as well as the model/in-simulator mismatch in the magnitude of the plant states when the other states match.

Research on integration of visual and motion cues for flight simulation and ride quality investigation

NASA Technical Reports Server (NTRS)

Young, L. R.; Oman, C. M.; Curry, R. E.

1977-01-01

Vestibular perception and integration of several sensory inputs in simulation were studied. The relationship between tilt sensation induced by moving fields and those produced by actual body tilt is discussed. Linearvection studies were included and the application of the vestibular model for perception of orientation based on motion cues is presented. Other areas of examination includes visual cues in approach to landing, and a comparison of linear and nonlinear wash out filters using a model of the human vestibular system is given.

Dysgranular Retrosplenial Cortex Lesions in Rats Disrupt Cross-Modal Object Recognition

ERIC Educational Resources Information Center

Hindley, Emma L.; Nelson, Andrew J. D.; Aggleton, John P.; Vann, Seralynne D.

2014-01-01

The retrosplenial cortex supports navigation, with one role thought to be the integration of different spatial cue types. This hypothesis was extended by examining the integration of nonspatial cues. Rats with lesions in either the dysgranular subregion of retrosplenial cortex (area 30) or lesions in both the granular and dysgranular subregions…

The Selective Cue Integration Framework: A Theory of Postidentification Witness Confidence Assessment

ERIC Educational Resources Information Center

Charman, Steve D.; Carlucci, Marianna; Vallano, Jon; Gregory, Amy Hyman

2010-01-01

The current manuscript proposes a theory of how witnesses assess their confidence following a lineup identification, called the selective cue integration framework (SCIF). Drawing from past research on the postidentification feedback effect, the SCIF details a three-stage process of confidence assessment that is based largely on a…

Cross-Frequency Integration for Consonant and Vowel Identification in Bimodal Hearing

ERIC Educational Resources Information Center

Kong, Ying-Yee; Braida, Louis D.

2011-01-01

Purpose: Improved speech recognition in binaurally combined acoustic-electric stimulation (otherwise known as "bimodal hearing") could arise when listeners integrate speech cues from the acoustic and electric hearing. The aims of this study were (a) to identify speech cues extracted in electric hearing and residual acoustic hearing in the…

Developments in Human Centered Cueing Algorithms for Control of Flight Simulator Motion Systems

NASA Technical Reports Server (NTRS)

Houck, Jacob A.; Telban, Robert J.; Cardullo, Frank M.

1997-01-01

The authors conducted further research with cueing algorithms for control of flight simulator motion systems. A variation of the so-called optimal algorithm was formulated using simulated aircraft angular velocity input as a basis. Models of the human vestibular sensation system, i.e. the semicircular canals and otoliths, are incorporated within the algorithm. Comparisons of angular velocity cueing responses showed a significant improvement over a formulation using angular acceleration input. Results also compared favorably with the coordinated adaptive washout algorithm, yielding similar results for angular velocity cues while eliminating false cues and reducing the tilt rate for longitudinal cues. These results were confirmed in piloted tests on the current motion system at NASA-Langley, the Visual Motion Simulator (VMS). Proposed future developments by the authors in cueing algorithms are revealed. The new motion system, the Cockpit Motion Facility (CMF), where the final evaluation of the cueing algorithms will be conducted, is also described.

Should visual speech cues (speechreading) be considered when fitting hearing aids?

NASA Astrophysics Data System (ADS)

Grant, Ken

2002-05-01

When talker and listener are face-to-face, visual speech cues become an important part of the communication environment, and yet, these cues are seldom considered when designing hearing aids. Models of auditory-visual speech recognition highlight the importance of complementary versus redundant speech information for predicting auditory-visual recognition performance. Thus, for hearing aids to work optimally when visual speech cues are present, it is important to know whether the cues provided by amplification and the cues provided by speechreading complement each other. In this talk, data will be reviewed that show nonmonotonicity between auditory-alone speech recognition and auditory-visual speech recognition, suggesting that efforts designed solely to improve auditory-alone recognition may not always result in improved auditory-visual recognition. Data will also be presented showing that one of the most important speech cues for enhancing auditory-visual speech recognition performance, voicing, is often the cue that benefits least from amplification.

Perceptual grouping in the human brain: common processing of different cues.

PubMed

Seymour, Kiley; Karnath, Hans-Otto; Himmelbach, Marc

2008-12-03

The perception of global scenes and objects consisting of multiple constituents is based on the integration of local elements or features. Gestalt grouping cues, such as proximity or similarity, can aid this process. Using functional MRI we investigated whether grouping guided by different gestalt cues rely on distinct networks in the brain or share a common network. Our study revealed that gestalt grouping involved the inferior parietal cortex, middle temporal gyrus and prefrontal cortex irrespective of the specific cue used. These findings agree with observations in neurological patients, which suggest that inferior parietal regions may aid the integration of local features into a global gestalt. Damage to this region results in simultanagnosia, a deficit in perceiving multiple objects and global scenes.

A randomized trial to determine the impact on compliance of a psychophysical peripheral cue based on the Elaboration Likelihood Model.

PubMed

Horton, Rachael Jane; Minniti, Antoinette; Mireylees, Stewart; McEntegart, Damian

2008-11-01

Non-compliance in clinical studies is a significant issue, but causes remain unclear. Utilizing the Elaboration Likelihood Model of persuasion, this study assessed the psychophysical peripheral cue 'Interactive Voice Response System (IVRS) call frequency' on compliance. 71 participants were randomized to once daily (OD), twice daily (BID) or three times daily (TID) call schedules over two weeks. Participants completed 30-item cognitive function tests at each call. Compliance was defined as proportion of expected calls within a narrow window (+/- 30 min around scheduled time), and within a relaxed window (-30 min to +4 h). Data were analyzed by ANOVA and pairwise comparisons adjusted by the Bonferroni correction. There was a relationship between call frequency and compliance. Bonferroni adjusted pairwise comparisons showed significantly higher compliance (p=0.03) for the BID (51.0%) than TID (30.3%) for the narrow window; for the extended window, compliance was higher (p=0.04) with OD (59.5%), than TID (38.4%). The IVRS psychophysical peripheral cue call frequency supported the ELM as a route to persuasion. The results also support OD strategy for optimal compliance. Models suggest specific indicators to enhance compliance with medication dosing and electronic patient diaries to improve health outcomes and data integrity respectively.

Promotion of Myogenic Maturation by Timely Application of Electric Field Along the Topographical Alignment.

PubMed

Ko, Ung Hyun; Park, Sukhee; Bang, Hyunseung; Kim, Mina; Shin, Hyunjun; Shin, Jennifer H

2018-05-01

Engineered muscular substitutes can restore the impaired muscle functions when integrated properly into the host tissue. To generate functional muscles with sufficient contractility at the site of transplant, the in vitro construction of fully differentiated muscle fibers would be desired. Many previous reports have identified either topographical alignment or electrical stimulation as an effective tool to promote myogenic differentiation. However, optimization of spatial and temporal arrangement of these two physical cues for better differentiation and maturation of skeletal muscles has not been investigated. In this article, we introduce a novel cell culture system that allows simultaneous application of these two independent directional cues at both orthogonal and parallel arrangements. We then show that the parallel arrangement of the aligned topography and the electric field synergistically facilitates better differentiation and maturation of C2C12, generating myotubes with more fused nuclei. Addition of the electric stimulation at the late stage of myogenic differentiation is found to further improve cell fusion to form multinucleate myotubes through a phosphatidylinositol-3-OH-kinase-dependent pathway. As such, we successfully demonstrated that the combined stimulation of topographical and electrical cues could effectively enhance both myogenic differentiation and maturation in a temporal and orientation-dependent manner, providing the basis for therapeutic strategies for regenerative tissue engineering.

The Modulation of Exogenous Spatial Cueing on Spatial Stroop Interference: Evidence of a Set for "Cue-Target Event Segregation"

ERIC Educational Resources Information Center

Funes, Maria Jesus; Lupianez, Juan; Milliken, Bruce

2008-01-01

Two experiments are reported that test whether the modulation of exogenous cuing effects by the presence of a distractor at the location opposite the target (altering the time course of cueing effects, Lupianez et al., 1999, 2001) is due to the fast reorienting of attention or to a set for preventing the integration of the cue and the target…

Neural Mechanism for Mirrored Self-face Recognition.

PubMed

Sugiura, Motoaki; Miyauchi, Carlos Makoto; Kotozaki, Yuka; Akimoto, Yoritaka; Nozawa, Takayuki; Yomogida, Yukihito; Hanawa, Sugiko; Yamamoto, Yuki; Sakuma, Atsushi; Nakagawa, Seishu; Kawashima, Ryuta

2015-09-01

Self-face recognition in the mirror is considered to involve multiple processes that integrate 2 perceptual cues: temporal contingency of the visual feedback on one's action (contingency cue) and matching with self-face representation in long-term memory (figurative cue). The aim of this study was to examine the neural bases of these processes by manipulating 2 perceptual cues using a "virtual mirror" system. This system allowed online dynamic presentations of real-time and delayed self- or other facial actions. Perception-level processes were identified as responses to only a single perceptual cue. The effect of the contingency cue was identified in the cuneus. The regions sensitive to the figurative cue were subdivided by the response to a static self-face, which was identified in the right temporal, parietal, and frontal regions, but not in the bilateral occipitoparietal regions. Semantic- or integration-level processes, including amodal self-representation and belief validation, which allow modality-independent self-recognition and the resolution of potential conflicts between perceptual cues, respectively, were identified in distinct regions in the right frontal and insular cortices. The results are supportive of the multicomponent notion of self-recognition and suggest a critical role for contingency detection in the co-emergence of self-recognition and empathy in infants. © The Author 2014. Published by Oxford University Press.

Neural Mechanism for Mirrored Self-face Recognition

PubMed Central

Sugiura, Motoaki; Miyauchi, Carlos Makoto; Kotozaki, Yuka; Akimoto, Yoritaka; Nozawa, Takayuki; Yomogida, Yukihito; Hanawa, Sugiko; Yamamoto, Yuki; Sakuma, Atsushi; Nakagawa, Seishu; Kawashima, Ryuta

2015-01-01

Self-face recognition in the mirror is considered to involve multiple processes that integrate 2 perceptual cues: temporal contingency of the visual feedback on one's action (contingency cue) and matching with self-face representation in long-term memory (figurative cue). The aim of this study was to examine the neural bases of these processes by manipulating 2 perceptual cues using a “virtual mirror” system. This system allowed online dynamic presentations of real-time and delayed self- or other facial actions. Perception-level processes were identified as responses to only a single perceptual cue. The effect of the contingency cue was identified in the cuneus. The regions sensitive to the figurative cue were subdivided by the response to a static self-face, which was identified in the right temporal, parietal, and frontal regions, but not in the bilateral occipitoparietal regions. Semantic- or integration-level processes, including amodal self-representation and belief validation, which allow modality-independent self-recognition and the resolution of potential conflicts between perceptual cues, respectively, were identified in distinct regions in the right frontal and insular cortices. The results are supportive of the multicomponent notion of self-recognition and suggest a critical role for contingency detection in the co-emergence of self-recognition and empathy in infants. PMID:24770712

Comparison of two weighted integration models for the cueing task: linear and likelihood

NASA Technical Reports Server (NTRS)

Shimozaki, Steven S.; Eckstein, Miguel P.; Abbey, Craig K.

2003-01-01

In a task in which the observer must detect a signal at two locations, presenting a precue that predicts the location of a signal leads to improved performance with a valid cue (signal location matches the cue), compared to an invalid cue (signal location does not match the cue). The cue validity effect has often been explained with a limited capacity attentional mechanism improving the perceptual quality at the cued location. Alternatively, the cueing effect can also be explained by unlimited capacity models that assume a weighted combination of noisy responses across the two locations. We compare two weighted integration models, a linear model and a sum of weighted likelihoods model based on a Bayesian observer. While qualitatively these models are similar, quantitatively they predict different cue validity effects as the signal-to-noise ratios (SNR) increase. To test these models, 3 observers performed in a cued discrimination task of Gaussian targets with an 80% valid precue across a broad range of SNR's. Analysis of a limited capacity attentional switching model was also included and rejected. The sum of weighted likelihoods model best described the psychophysical results, suggesting that human observers approximate a weighted combination of likelihoods, and not a weighted linear combination.

Normative Data on Audiovisual Speech Integration Using Sentence Recognition and Capacity Measures

PubMed Central

Altieri, Nicholas; Hudock, Daniel

2016-01-01

Objective The ability to use visual speech cues and integrate them with auditory information is important, especially in noisy environments and for hearing-impaired (HI) listeners. Providing data on measures of integration skills that encompass accuracy and processing speed will benefit researchers and clinicians. Design The study consisted of two experiments: First, accuracy scores were obtained using CUNY sentences, and capacity measures that assessed reaction-time distributions were obtained from a monosyllabic word recognition task. Study Sample We report data on two measures of integration obtained from a sample comprised of 86 young and middle-age adult listeners: Results To summarize our results, capacity showed a positive correlation with accuracy measures of audiovisual benefit obtained from sentence recognition. More relevant, factor analysis indicated that a single-factor model captured audiovisual speech integration better than models containing more factors. Capacity exhibited strong loadings on the factor, while the accuracy-based measures from sentence recognition exhibited weaker loadings. Conclusions Results suggest that a listener’s integration skills may be assessed optimally using a measure that incorporates both processing speed and accuracy. PMID:26853446

Normative data on audiovisual speech integration using sentence recognition and capacity measures.

PubMed

Altieri, Nicholas; Hudock, Daniel

2016-01-01

The ability to use visual speech cues and integrate them with auditory information is important, especially in noisy environments and for hearing-impaired (HI) listeners. Providing data on measures of integration skills that encompass accuracy and processing speed will benefit researchers and clinicians. The study consisted of two experiments: First, accuracy scores were obtained using City University of New York (CUNY) sentences, and capacity measures that assessed reaction-time distributions were obtained from a monosyllabic word recognition task. We report data on two measures of integration obtained from a sample comprised of 86 young and middle-age adult listeners: To summarize our results, capacity showed a positive correlation with accuracy measures of audiovisual benefit obtained from sentence recognition. More relevant, factor analysis indicated that a single-factor model captured audiovisual speech integration better than models containing more factors. Capacity exhibited strong loadings on the factor, while the accuracy-based measures from sentence recognition exhibited weaker loadings. Results suggest that a listener's integration skills may be assessed optimally using a measure that incorporates both processing speed and accuracy.

The Human Retrosplenial Cortex and Thalamus Code Head Direction in a Global Reference Frame.

PubMed

Shine, Jonathan P; Valdés-Herrera, José P; Hegarty, Mary; Wolbers, Thomas

2016-06-15

Spatial navigation is a multisensory process involving integration of visual and body-based cues. In rodents, head direction (HD) cells, which are most abundant in the thalamus, integrate these cues to code facing direction. Human fMRI studies examining HD coding in virtual environments (VE) have reported effects in retrosplenial complex and (pre-)subiculum, but not the thalamus. Furthermore, HD coding appeared insensitive to global landmarks. These tasks, however, provided only visual cues for orientation, and attending to global landmarks did not benefit task performance. In the present study, participants explored a VE comprising four separate locales, surrounded by four global landmarks. To provide body-based cues, participants wore a head-mounted display so that physical rotations changed facing direction in the VE. During subsequent MRI scanning, subjects saw stationary views of the environment and judged whether their orientation was the same as in the preceding trial. Parameter estimates extracted from retrosplenial cortex and the thalamus revealed significantly reduced BOLD responses when HD was repeated. Moreover, consistent with rodent findings, the signal did not continue to adapt over repetitions of the same HD. These results were supported by a whole-brain analysis showing additional repetition suppression in the precuneus. Together, our findings suggest that: (1) consistent with the rodent literature, the human thalamus may integrate visual and body-based, orientation cues; (2) global reference frame cues can be used to integrate HD across separate individual locales; and (3) immersive training procedures providing full body-based cues may help to elucidate the neural mechanisms supporting spatial navigation. In rodents, head direction (HD) cells signal facing direction in the environment via increased firing when the animal assumes a certain orientation. Distinct brain regions, the retrosplenial cortex (RSC) and thalamus, code for visual and vestibular cues of orientation, respectively. Putative HD signals have been observed in human RSC but not the thalamus, potentially because body-based cues were not provided. Here, participants encoded HD in a novel virtual environment while wearing a head-mounted display to provide body-based cues for orientation. In subsequent fMRI scanning, we found evidence of an HD signal in RSC, thalamus, and precuneus. These findings harmonize rodent and human data, and suggest that immersive training procedures provide a viable way to examine the neural basis of navigation. Copyright © 2016 the authors 0270-6474/16/366371-11$15.00/0.

Audio-visual onset differences are used to determine syllable identity for ambiguous audio-visual stimulus pairs

PubMed Central

ten Oever, Sanne; Sack, Alexander T.; Wheat, Katherine L.; Bien, Nina; van Atteveldt, Nienke

2013-01-01

Content and temporal cues have been shown to interact during audio-visual (AV) speech identification. Typically, the most reliable unimodal cue is used more strongly to identify specific speech features; however, visual cues are only used if the AV stimuli are presented within a certain temporal window of integration (TWI). This suggests that temporal cues denote whether unimodal stimuli belong together, that is, whether they should be integrated. It is not known whether temporal cues also provide information about the identity of a syllable. Since spoken syllables have naturally varying AV onset asynchronies, we hypothesize that for suboptimal AV cues presented within the TWI, information about the natural AV onset differences can aid in speech identification. To test this, we presented low-intensity auditory syllables concurrently with visual speech signals, and varied the stimulus onset asynchronies (SOA) of the AV pair, while participants were instructed to identify the auditory syllables. We revealed that specific speech features (e.g., voicing) were identified by relying primarily on one modality (e.g., auditory). Additionally, we showed a wide window in which visual information influenced auditory perception, that seemed even wider for congruent stimulus pairs. Finally, we found a specific response pattern across the SOA range for syllables that were not reliably identified by the unimodal cues, which we explained as the result of the use of natural onset differences between AV speech signals. This indicates that temporal cues not only provide information about the temporal integration of AV stimuli, but additionally convey information about the identity of AV pairs. These results provide a detailed behavioral basis for further neuro-imaging and stimulation studies to unravel the neurofunctional mechanisms of the audio-visual-temporal interplay within speech perception. PMID:23805110

Audio-visual onset differences are used to determine syllable identity for ambiguous audio-visual stimulus pairs.

PubMed

Ten Oever, Sanne; Sack, Alexander T; Wheat, Katherine L; Bien, Nina; van Atteveldt, Nienke

2013-01-01

Content and temporal cues have been shown to interact during audio-visual (AV) speech identification. Typically, the most reliable unimodal cue is used more strongly to identify specific speech features; however, visual cues are only used if the AV stimuli are presented within a certain temporal window of integration (TWI). This suggests that temporal cues denote whether unimodal stimuli belong together, that is, whether they should be integrated. It is not known whether temporal cues also provide information about the identity of a syllable. Since spoken syllables have naturally varying AV onset asynchronies, we hypothesize that for suboptimal AV cues presented within the TWI, information about the natural AV onset differences can aid in speech identification. To test this, we presented low-intensity auditory syllables concurrently with visual speech signals, and varied the stimulus onset asynchronies (SOA) of the AV pair, while participants were instructed to identify the auditory syllables. We revealed that specific speech features (e.g., voicing) were identified by relying primarily on one modality (e.g., auditory). Additionally, we showed a wide window in which visual information influenced auditory perception, that seemed even wider for congruent stimulus pairs. Finally, we found a specific response pattern across the SOA range for syllables that were not reliably identified by the unimodal cues, which we explained as the result of the use of natural onset differences between AV speech signals. This indicates that temporal cues not only provide information about the temporal integration of AV stimuli, but additionally convey information about the identity of AV pairs. These results provide a detailed behavioral basis for further neuro-imaging and stimulation studies to unravel the neurofunctional mechanisms of the audio-visual-temporal interplay within speech perception.

Transcriptional integration of mitogenic and mechanical signals by Myc and YAP.

PubMed

Croci, Ottavio; De Fazio, Serena; Biagioni, Francesca; Donato, Elisa; Caganova, Marieta; Curti, Laura; Doni, Mirko; Sberna, Silvia; Aldeghi, Deborah; Biancotto, Chiara; Verrecchia, Alessandro; Olivero, Daniela; Amati, Bruno; Campaner, Stefano

2017-10-15

Mammalian cells must integrate environmental cues to determine coherent physiological responses. The transcription factors Myc and YAP-TEAD act downstream from mitogenic signals, with the latter responding also to mechanical cues. Here, we show that these factors coordinately regulate genes required for cell proliferation. Activation of Myc led to extensive association with its genomic targets, most of which were prebound by TEAD. At these loci, recruitment of YAP was Myc-dependent and led to full transcriptional activation. This cooperation was critical for cell cycle entry, organ growth, and tumorigenesis. Thus, Myc and YAP-TEAD integrate mitogenic and mechanical cues at the transcriptional level to provide multifactorial control of cell proliferation. © 2017 Croci et al.; Published by Cold Spring Harbor Laboratory Press.

Is Posner's "beam" the same as Treisman's "glue"?: On the relation between visual orienting and feature integration theory.

PubMed

Briand, K A; Klein, R M

1987-05-01

In the present study we investigated whether the visually allocated "beam" studied by Posner and others is the same visual attentional resource that performs the role of feature integration in Treisman's model. Subjects were cued to attend to a certain spatial location by a visual cue, and performance at expected and unexpected stimulus locations was compared. Subjects searched for a target letter (R) with distractor letters that either could give rise to illusory conjunctions (PQ) or could not (PB). Results from three separate experiments showed that orienting attention in response to central cues (endogenous orienting) showed similar effects for both conjunction and feature search. However, when attention was oriented with peripheral visual cues (exogenous orienting), conjunction search showed larger effects of attention than did feature search. It is suggested that the attentional systems that are oriented in response to central and peripheral cues may not be the same and that only the latter performs a role in feature integration. Possibilities for future research are discussed.

Integrating cues of social interest and voice pitch in men's preferences for women's voices.

PubMed

Jones, Benedict C; Feinberg, David R; Debruine, Lisa M; Little, Anthony C; Vukovic, Jovana

2008-04-23

Most previous studies of vocal attractiveness have focused on preferences for physical characteristics of voices such as pitch. Here we examine the content of vocalizations in interaction with such physical traits, finding that vocal cues of social interest modulate the strength of men's preferences for raised pitch in women's voices. Men showed stronger preferences for raised pitch when judging the voices of women who appeared interested in the listener than when judging the voices of women who appeared relatively disinterested in the listener. These findings show that voice preferences are not determined solely by physical properties of voices and that men integrate information about voice pitch and the degree of social interest expressed by women when forming voice preferences. Women's preferences for raised pitch in women's voices were not modulated by cues of social interest, suggesting that the integration of cues of social interest and voice pitch when men judge the attractiveness of women's voices may reflect adaptations that promote efficient allocation of men's mating effort.

Modeling the Development of Audiovisual Cue Integration in Speech Perception

PubMed Central

Getz, Laura M.; Nordeen, Elke R.; Vrabic, Sarah C.; Toscano, Joseph C.

2017-01-01

Adult speech perception is generally enhanced when information is provided from multiple modalities. In contrast, infants do not appear to benefit from combining auditory and visual speech information early in development. This is true despite the fact that both modalities are important to speech comprehension even at early stages of language acquisition. How then do listeners learn how to process auditory and visual information as part of a unified signal? In the auditory domain, statistical learning processes provide an excellent mechanism for acquiring phonological categories. Is this also true for the more complex problem of acquiring audiovisual correspondences, which require the learner to integrate information from multiple modalities? In this paper, we present simulations using Gaussian mixture models (GMMs) that learn cue weights and combine cues on the basis of their distributional statistics. First, we simulate the developmental process of acquiring phonological categories from auditory and visual cues, asking whether simple statistical learning approaches are sufficient for learning multi-modal representations. Second, we use this time course information to explain audiovisual speech perception in adult perceivers, including cases where auditory and visual input are mismatched. Overall, we find that domain-general statistical learning techniques allow us to model the developmental trajectory of audiovisual cue integration in speech, and in turn, allow us to better understand the mechanisms that give rise to unified percepts based on multiple cues. PMID:28335558

Modeling the Development of Audiovisual Cue Integration in Speech Perception.

PubMed

Getz, Laura M; Nordeen, Elke R; Vrabic, Sarah C; Toscano, Joseph C

2017-03-21

Adult speech perception is generally enhanced when information is provided from multiple modalities. In contrast, infants do not appear to benefit from combining auditory and visual speech information early in development. This is true despite the fact that both modalities are important to speech comprehension even at early stages of language acquisition. How then do listeners learn how to process auditory and visual information as part of a unified signal? In the auditory domain, statistical learning processes provide an excellent mechanism for acquiring phonological categories. Is this also true for the more complex problem of acquiring audiovisual correspondences, which require the learner to integrate information from multiple modalities? In this paper, we present simulations using Gaussian mixture models (GMMs) that learn cue weights and combine cues on the basis of their distributional statistics. First, we simulate the developmental process of acquiring phonological categories from auditory and visual cues, asking whether simple statistical learning approaches are sufficient for learning multi-modal representations. Second, we use this time course information to explain audiovisual speech perception in adult perceivers, including cases where auditory and visual input are mismatched. Overall, we find that domain-general statistical learning techniques allow us to model the developmental trajectory of audiovisual cue integration in speech, and in turn, allow us to better understand the mechanisms that give rise to unified percepts based on multiple cues.

Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy covariance, biometric and continuous soil chamber measurements

NASA Astrophysics Data System (ADS)

Zanotelli, D.; Montagnani, L.; Manca, G.; Tagliavini, M.

2013-05-01

Carbon use efficiency (CUE), the ratio of net primary production (NPP) over gross primary production (GPP), is a functional parameter that could possibly link the current increasingly accurate global GPP estimates with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, NPP and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard, both net ecosystem production and gross primary production on a yearly basis, 380 ± 30 g C m-2 and 1263 ± 189 g C m-2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruit: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.12, was higher than the previously suggested constant values of 0.47-0.50. Low nitrogen investment in fruit, the limited root apparatus, and the optimal growth temperature and nutritional condition observed at the site are suggested to be explanatory variables for the high CUE observed.

Decision Environment and Heuristics in Individual and Collective Hypothesis Generation

DTIC Science & Technology

2017-11-01

number of images viewed: When the high -value cue appeared late in the trial, time pressure yielded hypothesis changes sooner than did no time pressure...However, when the high -value cue appeared early in the trial, time pressure had no effect on images viewed. Overall, participants’ timing was...scenarios. Cue order influenced the quality of timing. Participants were more likely to change their hypotheses at an optimal time when the high

Examining the Effect of Age on Visual-Vestibular Self-Motion Perception Using a Driving Paradigm.

PubMed

Ramkhalawansingh, Robert; Keshavarz, Behrang; Haycock, Bruce; Shahab, Saba; Campos, Jennifer L

2017-05-01

Previous psychophysical research has examined how younger adults and non-human primates integrate visual and vestibular cues to perceive self-motion. However, there is much to be learned about how multisensory self-motion perception changes with age, and how these changes affect performance on everyday tasks involving self-motion. Evidence suggests that older adults display heightened multisensory integration compared with younger adults; however, few previous studies have examined this for visual-vestibular integration. To explore age differences in the way that visual and vestibular cues contribute to self-motion perception, we had younger and older participants complete a basic driving task containing visual and vestibular cues. We compared their performance against a previously established control group that experienced visual cues alone. Performance measures included speed, speed variability, and lateral position. Vestibular inputs resulted in more precise speed control among older adults, but not younger adults, when traversing curves. Older adults demonstrated more variability in lateral position when vestibular inputs were available versus when they were absent. These observations align with previous evidence of age-related differences in multisensory integration and demonstrate that they may extend to visual-vestibular integration. These findings may have implications for vehicle and simulator design when considering older users.

Visual gate for brain-computer interfaces.

PubMed

Dias, N S; Jacinto, L R; Mendes, P M; Correia, J H

2009-01-01

Brain-Computer Interfaces (BCI) based on event related potentials (ERP) have been successfully developed for applications like virtual spellers and navigation systems. This study tests the use of visual stimuli unbalanced in the subject's field of view to simultaneously cue mental imagery tasks (left vs. right hand movement) and detect subject attention. The responses to unbalanced cues were compared with the responses to balanced cues in terms of classification accuracy. Subject specific ERP spatial filters were calculated for optimal group separation. The unbalanced cues appear to enhance early ERPs related to cue visuospatial processing that improved the classification accuracy (as low as 6%) of ERPs in response to left vs. right cues soon (150-200 ms) after the cue presentation. This work suggests that such visual interface may be of interest in BCI applications as a gate mechanism for attention estimation and validation of control decisions.

Integration of multiple intraguild predator cues for oviposition decisions by a predatory mite

PubMed Central

Walzer, Andreas; Schausberger, Peter

2012-01-01

In mutual intraguild predation (IGP), the role of individual guild members is strongly context dependent and, during ontogeny, can shift from an intraguild (IG) prey to a food competitor or to an IG predator. Consequently, recognition of an offspring's predator is more complex for IG than classic prey females. Thus, IG prey females should be able to modulate their oviposition decisions by integrating multiple IG predator cues and by experience. Using a guild of plant-inhabiting predatory mites sharing the spider mite Tetranychus urticae as prey and passing through ontogenetic role shifts in mutual IGP, we assessed the effects of single and combined direct cues of the IG predator Amblyseius andersoni (eggs and traces left by a female on the substrate) on prey patch selection and oviposition behaviour of naïve and IG predator-experienced IG prey females of Phytoseiulus persimilis. The IG prey females preferentially resided in patches without predator cues when the alternative patch contained traces of predator females or the cue combination. Preferential egg placement in patches without predator cues was only apparent in the choice situation with the cue combination. Experience increased the responsiveness of females exposed to the IG predator cue combination, indicated by immediate selection of the prey patch without predator cues and almost perfect oviposition avoidance in patches with the cue combination. We argue that the evolution of the ability of IG prey females to evaluate offspring's IGP risk accurately is driven by the irreversibility of oviposition and the functionally complex relationships between predator guild members. PMID:23264692

Emotional expression in music: contribution, linearity, and additivity of primary musical cues

PubMed Central

Eerola, Tuomas; Friberg, Anders; Bresin, Roberto

2013-01-01

The aim of this study is to manipulate musical cues systematically to determine the aspects of music that contribute to emotional expression, and whether these cues operate in additive or interactive fashion, and whether the cue levels can be characterized as linear or non-linear. An optimized factorial design was used with six primary musical cues (mode, tempo, dynamics, articulation, timbre, and register) across four different music examples. Listeners rated 200 musical examples according to four perceived emotional characters (happy, sad, peaceful, and scary). The results exhibited robust effects for all cues and the ranked importance of these was established by multiple regression. The most important cue was mode followed by tempo, register, dynamics, articulation, and timbre, although the ranking varied across the emotions. The second main result suggested that most cue levels contributed to the emotions in a linear fashion, explaining 77–89% of variance in ratings. Quadratic encoding of cues did lead to minor but significant increases of the models (0–8%). Finally, the interactions between the cues were non-existent suggesting that the cues operate mostly in an additive fashion, corroborating recent findings on emotional expression in music (Juslin and Lindström, 2010). PMID:23908642

Emotional expression in music: contribution, linearity, and additivity of primary musical cues.

PubMed

Eerola, Tuomas; Friberg, Anders; Bresin, Roberto

2013-01-01

The aim of this study is to manipulate musical cues systematically to determine the aspects of music that contribute to emotional expression, and whether these cues operate in additive or interactive fashion, and whether the cue levels can be characterized as linear or non-linear. An optimized factorial design was used with six primary musical cues (mode, tempo, dynamics, articulation, timbre, and register) across four different music examples. Listeners rated 200 musical examples according to four perceived emotional characters (happy, sad, peaceful, and scary). The results exhibited robust effects for all cues and the ranked importance of these was established by multiple regression. The most important cue was mode followed by tempo, register, dynamics, articulation, and timbre, although the ranking varied across the emotions. The second main result suggested that most cue levels contributed to the emotions in a linear fashion, explaining 77-89% of variance in ratings. Quadratic encoding of cues did lead to minor but significant increases of the models (0-8%). Finally, the interactions between the cues were non-existent suggesting that the cues operate mostly in an additive fashion, corroborating recent findings on emotional expression in music (Juslin and Lindström, 2010).

External and internal facial features modulate processing of vertical but not horizontal spatial relations.

PubMed

Meinhardt, Günter; Kurbel, David; Meinhardt-Injac, Bozana; Persike, Malte

2018-03-22

Some years ago an asymmetry was reported for the inversion effect for horizontal (H) and vertical (V) relational face manipulations (Goffaux & Rossion, 2007). Subsequent research examined whether a specific disruption of long-range relations underlies the H/V inversion asymmetry (Sekunova & Barton, 2008). Here, we tested how detection of changes in interocular distance (H) and eye height (V) depends on cardinal internal features and external feature surround. Results replicated the H/V inversion asymmetry. Moreover, we found very different face cue dependencies for both change types. Performance and inversion effects did not depend on the presence of other face cues for detecting H changes. In contrast, accuracy for detecting V changes strongly depended on internal and external features, showing cumulative improvement when more cues were added. Inversion effects were generally large, and larger with external feature surround. The cue independence in detecting H relational changes indicates specialized local processing tightly tuned to the eyes region, while the strong cue dependency in detecting V relational changes indicates a global mechanism of cue integration across different face regions. These findings suggest that the H/V asymmetry of the inversion effect rests on an H/V anisotropy of face cue dependency, since only the global V mechanism suffers from disruption of cue integration as the major effect of face inversion. Copyright © 2018. Published by Elsevier Ltd.

Cue Integration in Dynamic Decision Marking (Integration des indices dans la Prise de Decision Dynamique)

DTIC Science & Technology

2010-07-01

e.g., pulling the goalie in hockey). Outcomes are thought of as changes from a reference point- the reference point is itself changed by how the...challenges and training related issues can be pulled from the literature. These are discussed below. General Themes Cue integration involves the use...from our understanding of the term "pattern recognition", a number of general themes, challenges and training related issues can be pulled from the

Effects of Prosodic Cues on Topic Continuity in Child Language Production

ERIC Educational Resources Information Center

Vernice, Mirta; Guasti, Maria Teresa

2014-01-01

It remains controversial whether children are able to process and integrate specific linguistic cues in their mental model to the same extent as adults. In the present study, a sentence continuation task was employed to determine how Italian speakers (4-, 5-, 6-year-olds and adults) interpret prosodic cues to decide which referent is more salient…

Integration of visual and motion cues for simulator requirements and ride quality investigation

NASA Technical Reports Server (NTRS)

Young, L. R.

1976-01-01

Practical tools which can extend the state of the art of moving base flight simulation for research and training are developed. Main approaches to this research effort include: (1) application of the vestibular model for perception of orientation based on motion cues: optimum simulator motion controls; and (2) visual cues in landing.

The Influence of Surface and Deep Cues on Primary and Secondary School Students' Assessment of Relevance in Web Menus

ERIC Educational Resources Information Center

Rouet, Jean-Francois; Ros, Christine; Goumi, Antonine; Macedo-Rouet, Monica; Dinet, Jerome

2011-01-01

Two experiments investigated primary and secondary school students' Web menu selection strategies using simulated Web search tasks. It was hypothesized that students' selections of websites depend on their perception and integration of multiple relevance cues. More specifically, students should be able to disentangle superficial cues (e.g.,…

Reversals and collisions optimize protein exchange in bacterial swarms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amiri, Aboutaleb; Harvey, Cameron; Buchmann, Amy

Swarming groups of bacteria coordinate their behavior by self-organizing as a population to move over surfaces in search of nutrients and optimal niches for colonization. Many open questions remain about the cues used by swarming bacteria to achieve this self-organization. While chemical cue signaling known as quorum sensing is well-described, swarming bacteria often act and coordinate on time scales that could not be achieved via these extracellular quorum sensing cues. Here, cell-cell contact-dependent protein exchange is explored as amechanism of intercellular signaling for the bacterium Myxococcus xanthus. A detailed biologically calibrated computational model is used to study how M. xanthusmore » optimizes the connection rate between cells and maximizes the spread of an extracellular protein within the population. The maximum rate of protein spreading is observed for cells that reverse direction optimally for swarming. Cells that reverse too slowly or too fast fail to spread extracellular protein efficiently. In particular, a specific range of cell reversal frequencies was observed to maximize the cell-cell connection rate and minimize the time of protein spreading. Furthermore, our findings suggest that predesigned motion reversal can be employed to enhance the collective behavior of biological synthetic active systems.« less

Linking attentional processes and conceptual problem solving: visual cues facilitate the automaticity of extracting relevant information from diagrams

PubMed Central

Rouinfar, Amy; Agra, Elise; Larson, Adam M.; Rebello, N. Sanjay; Loschky, Lester C.

2014-01-01

This study investigated links between visual attention processes and conceptual problem solving. This was done by overlaying visual cues on conceptual physics problem diagrams to direct participants’ attention to relevant areas to facilitate problem solving. Participants (N = 80) individually worked through four problem sets, each containing a diagram, while their eye movements were recorded. Each diagram contained regions that were relevant to solving the problem correctly and separate regions related to common incorrect responses. Problem sets contained an initial problem, six isomorphic training problems, and a transfer problem. The cued condition saw visual cues overlaid on the training problems. Participants’ verbal responses were used to determine their accuracy. This study produced two major findings. First, short duration visual cues which draw attention to solution-relevant information and aid in the organizing and integrating of it, facilitate both immediate problem solving and generalization of that ability to new problems. Thus, visual cues can facilitate re-representing a problem and overcoming impasse, enabling a correct solution. Importantly, these cueing effects on problem solving did not involve the solvers’ attention necessarily embodying the solution to the problem, but were instead caused by solvers attending to and integrating relevant information in the problems into a solution path. Second, this study demonstrates that when such cues are used across multiple problems, solvers can automatize the extraction of problem-relevant information extraction. These results suggest that low-level attentional selection processes provide a necessary gateway for relevant information to be used in problem solving, but are generally not sufficient for correct problem solving. Instead, factors that lead a solver to an impasse and to organize and integrate problem information also greatly facilitate arriving at correct solutions. PMID:25324804

Linking attentional processes and conceptual problem solving: visual cues facilitate the automaticity of extracting relevant information from diagrams.

PubMed

Rouinfar, Amy; Agra, Elise; Larson, Adam M; Rebello, N Sanjay; Loschky, Lester C

2014-01-01

This study investigated links between visual attention processes and conceptual problem solving. This was done by overlaying visual cues on conceptual physics problem diagrams to direct participants' attention to relevant areas to facilitate problem solving. Participants (N = 80) individually worked through four problem sets, each containing a diagram, while their eye movements were recorded. Each diagram contained regions that were relevant to solving the problem correctly and separate regions related to common incorrect responses. Problem sets contained an initial problem, six isomorphic training problems, and a transfer problem. The cued condition saw visual cues overlaid on the training problems. Participants' verbal responses were used to determine their accuracy. This study produced two major findings. First, short duration visual cues which draw attention to solution-relevant information and aid in the organizing and integrating of it, facilitate both immediate problem solving and generalization of that ability to new problems. Thus, visual cues can facilitate re-representing a problem and overcoming impasse, enabling a correct solution. Importantly, these cueing effects on problem solving did not involve the solvers' attention necessarily embodying the solution to the problem, but were instead caused by solvers attending to and integrating relevant information in the problems into a solution path. Second, this study demonstrates that when such cues are used across multiple problems, solvers can automatize the extraction of problem-relevant information extraction. These results suggest that low-level attentional selection processes provide a necessary gateway for relevant information to be used in problem solving, but are generally not sufficient for correct problem solving. Instead, factors that lead a solver to an impasse and to organize and integrate problem information also greatly facilitate arriving at correct solutions.

Olfactory-visual integration facilitates perception of subthreshold negative emotion.

PubMed

Novak, Lucas R; Gitelman, Darren R; Schuyler, Brianna; Li, Wen

2015-10-01

A fast growing literature of multisensory emotion integration notwithstanding, the chemical senses, intimately associated with emotion, have been largely overlooked. Moreover, an ecologically highly relevant principle of "inverse effectiveness", rendering maximal integration efficacy with impoverished sensory input, remains to be assessed in emotion integration. Presenting minute, subthreshold negative (vs. neutral) cues in faces and odors, we demonstrated olfactory-visual emotion integration in improved emotion detection (especially among individuals with weaker perception of unimodal negative cues) and response enhancement in the amygdala. Moreover, while perceptual gain for visual negative emotion involved the posterior superior temporal sulcus/pSTS, perceptual gain for olfactory negative emotion engaged both the associative olfactory (orbitofrontal) cortex and amygdala. Dynamic causal modeling (DCM) analysis of fMRI timeseries further revealed connectivity strengthening among these areas during crossmodal emotion integration. That multisensory (but not low-level unisensory) areas exhibited both enhanced response and region-to-region coupling favors a top-down (vs. bottom-up) account for olfactory-visual emotion integration. Current findings thus confirm the involvement of multisensory convergence areas, while highlighting unique characteristics of olfaction-related integration. Furthermore, successful crossmodal binding of subthreshold aversive cues not only supports the principle of "inverse effectiveness" in emotion integration but also accentuates the automatic, unconscious quality of crossmodal emotion synthesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Feature integration and spatial attention: common processes for endogenous and exogenous orienting.

PubMed

Henderickx, David; Maetens, Kathleen; Soetens, Eric

2010-05-01

Briand (J Exp Psychol Hum Percept Perform 24:1243-1256, 1998) and Briand and Klein (J Exp Psychol Hum Percept Perform 13:228-241, 1987) demonstrated that spatial cueing effects are larger for detecting conjunction of features than for detecting simple features when spatial attention is oriented exogenously, and not when attention is oriented endogenously. Their results were interpreted as if only exogenous attention affects the posterior spatial attention system that performs the feature binding function attributed to spatial attention by Treisman's feature integration theory (FIT; 1980). In a series of 6 experiments, we attempted to replicate Briand's findings. Manipulations of distractor string size and symmetry of stimulus presentation left and right from fixation were implemented in Posner's cueing paradigm. The data indicate that both exogenous and endogenous cueing address the same attentional mechanism needed for feature binding. The results also limit the generalisability of Briand's proposal concerning the role of exogenous attention in feature integration. Furthermore, the importance to control the effect of unintended attentional capture in a cueing task is demonstrated.

Integration of Distinct Objects in Visual Working Memory Depends on Strong Objecthood Cues Even for Different-Dimension Conjunctions.

PubMed

Balaban, Halely; Luria, Roy

2016-05-01

What makes an integrated object in visual working memory (WM)? Past evidence suggested that WM holds all features of multidimensional objects together, but struggles to integrate color-color conjunctions. This difficulty was previously attributed to a challenge in same-dimension integration, but here we argue that it arises from the integration of 2 distinct objects. To test this, we examined the integration of distinct different-dimension features (a colored square and a tilted bar). We monitored the contralateral delay activity, an event-related potential component sensitive to the number of objects in WM. The results indicated that color and orientation belonging to distinct objects in a shared location were not integrated in WM (Experiment 1), even following a common fate Gestalt cue (Experiment 2). These conjunctions were better integrated in a less demanding task (Experiment 3), and in the original WM task, but with a less individuating version of the original stimuli (Experiment 4). Our results identify the critical factor in WM integration at same- versus separate-objects, rather than at same- versus different-dimensions. Compared with the perfect integration of an object's features, the integration of several objects is demanding, and depends on an interaction between the grouping cues and task demands, among other factors. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Cue-induced Behavioral and Neural Changes among Excessive Internet Gamers and Possible Application of Cue Exposure Therapy to Internet Gaming Disorder.

PubMed

Zhang, Yongjun; Ndasauka, Yamikani; Hou, Juan; Chen, Jiawen; Yang, Li Zhuang; Wang, Ying; Han, Long; Bu, Junjie; Zhang, Peng; Zhou, Yifeng; Zhang, Xiaochu

2016-01-01

Internet gaming disorder (IGD) may lead to many negative consequences in everyday life, yet there is currently no effective treatment for IGD. Cue-reactivity paradigm is commonly used to evaluate craving for substance, food, and gambling; cue exposure therapy (CET) is applied to treating substance use disorders (SUDs) and some other psychological disorders such as pathological gambling (PG). However, no study has explored CET's application to the treatment of IGD except two articles having implied that cues' exposure may have therapeutic effect on IGD. This paper reviews studies on cue-induced behavioral and neural changes in excessive Internet gamers, indicating that behavioral and neural mechanisms of IGD mostly overlap with those of SUD. The CET's effects in the treatment of SUDs and PG are also reviewed. We finally propose an optimized CET paradigm, which future studies should consider and investigate as a probable treatment of IGD.

A model for the pilot's use of motion cues in roll-axis tracking tasks

NASA Technical Reports Server (NTRS)

Levison, W. H.; Junker, A. M.

1977-01-01

Simulated target-following and disturbance-regulation tasks were explored with subjects using visual-only and combined visual and motion cues. The effects of motion cues on task performance and pilot response behavior were appreciably different for the two task configurations and were consistent with data reported in earlier studies for similar task configurations. The optimal-control model for pilot/vehicle systems provided a task-independent framework for accounting for the pilot's use of motion cues. Specifically, the availability of motion cues was modeled by augmenting the set of perceptual variables to include position, rate, acceleration, and accleration-rate of the motion simulator, and results were consistent with the hypothesis of attention-sharing between visual and motion variables. This straightforward informational model allowed accurate model predictions of the effects of motion cues on a variety of response measures for both the target-following and disturbance-regulation tasks.

The Effective Use of Symbols in Teaching Word Recognition to Children with Severe Learning Difficulties: A Comparison of Word Alone, Integrated Picture Cueing and the Handle Technique.

ERIC Educational Resources Information Center

Sheehy, Kieron

2002-01-01

A comparison is made between a new technique (the Handle Technique), Integrated Picture Cueing, and a Word Alone Method. Results show using a new combination of teaching strategies enabled logographic symbols to be used effectively in teaching word recognition to 12 children with severe learning difficulties. (Contains references.) (Author/CR)

Object representations in visual working memory change according to the task context.

PubMed

Balaban, Halely; Luria, Roy

2016-08-01

This study investigated whether an item's representation in visual working memory (VWM) can be updated according to changes in the global task context. We used a modified change detection paradigm, in which the items moved before the retention interval. In all of the experiments, we presented identical color-color conjunction items that were arranged to provide a common fate Gestalt grouping cue during their movement. Task context was manipulated by adding a condition highlighting either the integrated interpretation of the conjunction items or their individuated interpretation. We monitored the contralateral delay activity (CDA) as an online marker of VWM. Experiment 1 employed only a minimal global context; the conjunction items were integrated during their movement, but then were partially individuated, at a late stage of the retention interval. The same conjunction items were perfectly integrated in an integration context (Experiment 2). An individuation context successfully produced strong individuation, already during the movement, overriding Gestalt grouping cues (Experiment 3). In Experiment 4, a short priming of the individuation context managed to individuate the conjunction items immediately after the Gestalt cue was no longer available. Thus, the representations of identical items changed according to the task context, suggesting that VWM interprets incoming input according to global factors which can override perceptual cues. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gait parameter control timing with dynamic manual contact or visual cues

PubMed Central

Shi, Peter; Werner, William

2016-01-01

We investigated the timing of gait parameter changes (stride length, peak toe velocity, and double-, single-support, and complete step duration) to control gait speed. Eleven healthy participants adjusted their gait speed on a treadmill to maintain a constant distance between them and a fore-aft oscillating cue (a place on a conveyor belt surface). The experimental design balanced conditions of cue modality (vision: eyes-open; manual contact: eyes-closed while touching the cue); treadmill speed (0.2, 0.4, 0.85, and 1.3 m/s); and cue motion (none, ±10 cm at 0.09, 0.11, and 0.18 Hz). Correlation analyses revealed a number of temporal relationships between gait parameters and cue speed. The results suggest that neural control ranged from feedforward to feedback. Specifically, step length preceded cue velocity during double-support duration suggesting anticipatory control. Peak toe velocity nearly coincided with its most-correlated cue velocity during single-support duration. The toe-off concluding step and double-support durations followed their most-correlated cue velocity, suggesting feedback control. Cue-tracking accuracy and cue velocity correlations with timing parameters were higher with the manual contact cue than visual cue. The cue/gait timing relationships generalized across cue modalities, albeit with greater delays of step-cycle events relative to manual contact cue velocity. We conclude that individual kinematic parameters of gait are controlled to achieve a desired velocity at different specific times during the gait cycle. The overall timing pattern of instantaneous cue velocities associated with different gait parameters is conserved across cues that afford different performance accuracies. This timing pattern may be temporally shifted to optimize control. Different cue/gait parameter latencies in our nonadaptation paradigm provide general-case evidence of the independent control of gait parameters previously demonstrated in gait adaptation paradigms. PMID:26936979

Online games: a novel approach to explore how partial information influences human random searches

NASA Astrophysics Data System (ADS)

Martínez-García, Ricardo; Calabrese, Justin M.; López, Cristóbal

2017-01-01

Many natural processes rely on optimizing the success ratio of a search process. We use an experimental setup consisting of a simple online game in which players have to find a target hidden on a board, to investigate how the rounds are influenced by the detection of cues. We focus on the search duration and the statistics of the trajectories traced on the board. The experimental data are explained by a family of random-walk-based models and probabilistic analytical approximations. If no initial information is given to the players, the search is optimized for cues that cover an intermediate spatial scale. In addition, initial information about the extension of the cues results, in general, in faster searches. Finally, strategies used by informed players turn into non-stationary processes in which the length of e ach displacement evolves to show a well-defined characteristic scale that is not found in non-informed searches.

Biomimetic Silk Scaffolds with an Amorphous Structure for Soft Tissue Engineering.

PubMed

Sang, Yonghuan; Li, Meirong; Liu, Jiejie; Yao, Yuling; Ding, Zhaozhao; Wang, Lili; Xiao, Liying; Lu, Qiang; Fu, Xiaobing; Kaplan, David L

2018-03-21

Fine tuning physical cues of silk fibroin (SF) biomaterials to match specific requirements for different soft tissues would be advantageous. Here, amorphous SF nanofibers were used to fabricate scaffolds with better hierarchical extracellular matrix (ECM) mimetic microstructures than previous silk scaffolds. Kinetic control was introduced into the scaffold forming process, resulting in the direct production of water-stable scaffolds with tunable secondary structures and thus mechanical properties. These biomaterials remained with amorphous structures, offering softer properties than prior scaffolds. The fine mechanical tunability of these systems provides a feasible way to optimize physical cues for improved cell proliferation and enhanced neovascularization in vivo. Multiple physical cues, such as partly ECM mimetic structures and optimized stiffness, provided suitable microenvironments for tissue ingrowth, suggesting the possibility of actively designing bioactive SF biomaterials. These systems suggest a promising strategy to develop novel SF biomaterials for soft tissue repair and regenerative medicine.

Online games: a novel approach to explore how partial information influences human random searches.

PubMed

Martínez-García, Ricardo; Calabrese, Justin M; López, Cristóbal

2017-01-06

Many natural processes rely on optimizing the success ratio of a search process. We use an experimental setup consisting of a simple online game in which players have to find a target hidden on a board, to investigate how the rounds are influenced by the detection of cues. We focus on the search duration and the statistics of the trajectories traced on the board. The experimental data are explained by a family of random-walk-based models and probabilistic analytical approximations. If no initial information is given to the players, the search is optimized for cues that cover an intermediate spatial scale. In addition, initial information about the extension of the cues results, in general, in faster searches. Finally, strategies used by informed players turn into non-stationary processes in which the length of e ach displacement evolves to show a well-defined characteristic scale that is not found in non-informed searches.

Effects of Hydrogel Stiffness and Extracellular Compositions on Modulating Cartilage Regeneration by Mixed Populations of Stem Cells and Chondrocytes In Vivo.

PubMed

Wang, Tianyi; Lai, Janice H; Yang, Fan

2016-12-01

Cell-based therapies offer great promise for repairing cartilage. Previous strategies often involved using a single cell population such as stem cells or chondrocytes. A mixed cell population may offer an alternative strategy for cartilage regeneration while overcoming donor scarcity. We have recently reported that adipose-derived stem cells (ADSCs) can catalyze neocartilage formation by neonatal chondrocytes (NChons) when mixed co-cultured in 3D hydrogels in vitro. However, it remains unknown how the biochemical and mechanical cues of hydrogels modulate cartilage formation by mixed cell populations in vivo. The present study seeks to answer this question by co-encapsulating ADSCs and NChons in 3D hydrogels with tunable stiffness (∼1-33 kPa) and biochemical cues, and evaluating cartilage formation in vivo using a mouse subcutaneous model. Three extracellular matrix molecules were examined, including chondroitin sulfate (CS), hyaluronic acid (HA), and heparan sulfate (HS). Our results showed that the type of biochemical cue played a dominant role in modulating neocartilage deposition. CS and HA enhanced type II collagen deposition, a desirable phenotype for articular cartilage. In contrast, HS promoted fibrocartilage phenotype with the upregulation of type I collagen and failed to retain newly deposited matrix. Hydrogels with stiffnesses of ∼7-33 kPa led to a comparable degree of neocartilage formation, and a minimal initial stiffness was required to retain hydrogel integrity over time. Results from this study highlight the important role of matrix cues in directing neocartilage formation, and they offer valuable insights in guiding optimal scaffold design for cartilage regeneration by using mixed cell populations.

Developing a new case based computer-aided detection scheme and an adaptive cueing method to improve performance in detecting mammographic lesions

PubMed Central

Tan, Maxine; Aghaei, Faranak; Wang, Yunzhi; Zheng, Bin

2017-01-01

The purpose of this study is to evaluate a new method to improve performance of computer-aided detection (CAD) schemes of screening mammograms with two approaches. In the first approach, we developed a new case based CAD scheme using a set of optimally selected global mammographic density, texture, spiculation, and structural similarity features computed from all four full-field digital mammography (FFDM) images of the craniocaudal (CC) and mediolateral oblique (MLO) views by using a modified fast and accurate sequential floating forward selection feature selection algorithm. Selected features were then applied to a “scoring fusion” artificial neural network (ANN) classification scheme to produce a final case based risk score. In the second approach, we combined the case based risk score with the conventional lesion based scores of a conventional lesion based CAD scheme using a new adaptive cueing method that is integrated with the case based risk scores. We evaluated our methods using a ten-fold cross-validation scheme on 924 cases (476 cancer and 448 recalled or negative), whereby each case had all four images from the CC and MLO views. The area under the receiver operating characteristic curve was AUC = 0.793±0.015 and the odds ratio monotonically increased from 1 to 37.21 as CAD-generated case based detection scores increased. Using the new adaptive cueing method, the region based and case based sensitivities of the conventional CAD scheme at a false positive rate of 0.71 per image increased by 2.4% and 0.8%, respectively. The study demonstrated that supplementary information can be derived by computing global mammographic density image features to improve CAD-cueing performance on the suspicious mammographic lesions. PMID:27997380

Integrated Testing and Maintenance Technologies.

DTIC Science & Technology

1983-12-01

provides pilot cueing for mode failures of LRU’s. Equipment fail and status indicators are lighted displays that indicate specific failures within an...provided with appropriate display cueing only when a reversion results in some loss of capability or performance. Three forms of degraded mode advisories...are- a. Reversion to an alternative data source of equivalent accuracy with no pilot cueing . b. Reversion to an alternative data source of lesser

Temporal and peripheral extraction of contextual cues from scenes during visual search.

PubMed

Koehler, Kathryn; Eckstein, Miguel P

2017-02-01

Scene context is known to facilitate object recognition and guide visual search, but little work has focused on isolating image-based cues and evaluating their contributions to eye movement guidance and search performance. Here, we explore three types of contextual cues (a co-occurring object, the configuration of other objects, and the superordinate category of background elements) and assess their joint contributions to search performance in the framework of cue-combination and the temporal unfolding of their extraction. We also assess whether observers' ability to extract each contextual cue in the visual periphery is a bottleneck that determines the utilization and contribution of each cue to search guidance and decision accuracy. We find that during the first four fixations of a visual search task observers first utilize the configuration of objects for coarse eye movement guidance and later use co-occurring object information for finer guidance. In the absence of contextual cues, observers were suboptimally biased to report the target object as being absent. The presence of the co-occurring object was the only contextual cue that had a significant effect in reducing decision bias. The early influence of object-based cues on eye movements is corroborated by a clear demonstration of observers' ability to extract object cues up to 16° into the visual periphery. The joint contributions of the cues to decision search accuracy approximates that expected from the combination of statistically independent cues and optimal cue combination. Finally, the lack of utilization and contribution of the background-based contextual cue to search guidance cannot be explained by the availability of the contextual cue in the visual periphery; instead it is related to background cues providing the least inherent information about the precise location of the target in the scene.

Understanding and mimicking the dual optimality of the fly ear

NASA Astrophysics Data System (ADS)

Liu, Haijun; Currano, Luke; Gee, Danny; Helms, Tristan; Yu, Miao

2013-08-01

The fly Ormia ochracea has the remarkable ability, given an eardrum separation of only 520 μm, to pinpoint the 5 kHz chirp of its cricket host. Previous research showed that the two eardrums are mechanically coupled, which amplifies the directional cues. We have now performed a mechanics and optimization analysis which reveals that the right coupling strength is key: it results in simultaneously optimized directional sensitivity and directional cue linearity at 5 kHz. We next demonstrated that this dual optimality is replicable in a synthetic device and can be tailored for a desired frequency. Finally, we demonstrated a miniature sensor endowed with this dual-optimality at 8 kHz with unparalleled sound localization. This work provides a quantitative and mechanistic explanation for the fly's sound-localization ability from a new perspective, and it provides a framework for the development of fly-ear inspired sensors to overcoming a previously-insurmountable size constraint in engineered sound-localization systems.

Multiple Fingers - One Gestalt.

PubMed

Lezkan, Alexandra; Manuel, Steven G; Colgate, J Edward; Klatzky, Roberta L; Peshkin, Michael A; Drewing, Knut

2016-01-01

The Gestalt theory of perception offered principles by which distributed visual sensations are combined into a structured experience ("Gestalt"). We demonstrate conditions whereby haptic sensations at two fingertips are integrated in the perception of a single object. When virtual bumps were presented simultaneously to the right hand's thumb and index finger during lateral arm movements, participants reported perceiving a single bump. A discrimination task measured the bump's perceived location and perceptual reliability (assessed by differential thresholds) for four finger configurations, which varied in their adherence to the Gestalt principles of proximity (small versus large finger separation) and synchrony (virtual spring to link movements of the two fingers versus no spring). According to models of integration, reliability should increase with the degree to which multi-finger cues integrate into a unified percept. Differential thresholds were smaller in the virtual-spring condition (synchrony) than when fingers were unlinked. Additionally, in the condition with reduced synchrony, greater proximity led to lower differential thresholds. Thus, with greater adherence to Gestalt principles, thresholds approached values predicted for optimal integration. We conclude that the Gestalt principles of synchrony and proximity apply to haptic perception of surface properties and that these principles can interact to promote multi-finger integration.

Gestalt Breastfeeding: Helping Mothers and Infants Optimize Positional Stability and Intraoral Breast Tissue Volume for Effective, Pain-Free Milk Transfer.

PubMed

Douglas, Pamela; Keogh, Renee

2017-08-01

In the past decade, biological nurturing and activation of maternal and infant instincts after birth have constituted a major advance in clinical breastfeeding support. Yet, physiologic breastfeeding initiation is not enough to ensure ongoing pain-free and effective breastfeeding for many pairs. Current interventions, including "hands-off" mammalian approaches, do not improve breastfeeding outcomes, including in randomized controlled trials. Back-arching, difficulty latching or staying on the breast, and fussing at the breast are common signs of infant positional instability during breastfeeding. These cues are, however, often misdiagnosed as signs of medical conditions or oral connective tissue abnormalities, and underlying positional instability is not addressed. New clinical approaches are urgently required. This article offers a clinical approach to fit and hold (or latch and positioning)- gestalt breastfeeding, which aims to optimize positional stability and intraoral breast tissue volumes for pain-free effective breastfeeding. The word gestalt (pronounced "ger-shtolt") means a whole that is more than the sum of its parts. Gestalt breastfeeding builds on the theoretical foundations of complexity science, physiologic breastfeeding initiation, and new understandings of the biomechanics of infant suck elucidated in ultrasound studies. It also integrates simple psychological strategies from applied functional contextualism, popularly known as Acceptance and Commitment Therapy, empowering women to attend mindfully to breast sensations and their infant's cues. Gestalt breastfeeding can be reproduced for research purposes, including in comparison studies with oral surgery, and has the potential to improve breastfeeding outcomes.

Are computers effective lie detectors? A meta-analysis of linguistic cues to deception.

PubMed

Hauch, Valerie; Blandón-Gitlin, Iris; Masip, Jaume; Sporer, Siegfried L

2015-11-01

This meta-analysis investigates linguistic cues to deception and whether these cues can be detected with computer programs. We integrated operational definitions for 79 cues from 44 studies where software had been used to identify linguistic deception cues. These cues were allocated to six research questions. As expected, the meta-analyses demonstrated that, relative to truth-tellers, liars experienced greater cognitive load, expressed more negative emotions, distanced themselves more from events, expressed fewer sensory-perceptual words, and referred less often to cognitive processes. However, liars were not more uncertain than truth-tellers. These effects were moderated by event type, involvement, emotional valence, intensity of interaction, motivation, and other moderators. Although the overall effect size was small, theory-driven predictions for certain cues received support. These findings not only further our knowledge about the usefulness of linguistic cues to detect deception with computers in applied settings but also elucidate the relationship between language and deception. © 2014 by the Society for Personality and Social Psychology, Inc.

Mini Review: Biomaterials for Enhancing Neuronal Repair

NASA Astrophysics Data System (ADS)

Cangellaris, Olivia V.; Gillette, Martha U.

2018-04-01

As they differentiate from neuroblasts, nascent neurons become highly polarized and elongate. Neurons extend and elaborate fine and fragile cellular extensions that form circuits enabling long-distance communication and signal integration within the body. While other organ systems are developing, projections of differentiating neurons find paths to distant targets. Subsequent post-developmental neuronal damage is catastrophic because the cues for reinnervation are no longer active. Advances in biomaterials are enabling fabrication of micro-environments that encourage neuronal regrowth and restoration of function by recreating these developmental cues. This mini-review considers new materials that employ topographical, chemical, electrical, and/or mechanical cues for use in neuronal repair. Manipulating and integrating these elements in different combinations will generate new technologies to enhance neural repair.

Does Contextual Cueing Guide the Deployment of Attention?

PubMed Central

Kunar, Melina A.; Flusberg, Stephen; Horowitz, Todd S.; Wolfe, Jeremy M.

2008-01-01

Contextual cueing experiments show that when displays are repeated, reaction times (RTs) to find a target decrease over time even when observers are not aware of the repetition. It has been thought that the context of the display guides attention to the target. We tested this hypothesis by comparing the effects of guidance in a standard search task to the effects of contextual cueing. Firstly, in standard search, an improvement in guidance causes search slopes (derived from RT × Set Size functions) to decrease. In contrast, we found that search slopes in contextual cueing did not become more efficient over time (Experiment 1). Secondly, when guidance is optimal (e.g. in easy feature search) we still found a small, but reliable contextual cueing effect (Experiments 2a and 2b), suggesting that other factors, such as response selection, contribute to the effect. Experiment 3 supported this hypothesis by showing that the contextual cueing effect disappeared when we added interference to the response selection process. Overall, our data suggest that the relationship between guidance and contextual cueing is weak and that response selection can account for part of the effect. PMID:17683230

Optimal assessment of multiple cues.

PubMed Central

Fawcett, Tim W; Johnstone, Rufus A

2003-01-01

In a wide range of contexts from mate choice to foraging, animals are required to discriminate between alternative options on the basis of multiple cues. How should they best assess such complex multicomponent stimuli? Here, we construct a model to investigate this problem, focusing on a simple case where a 'chooser' faces a discrimination task involving two cues. These cues vary in their accuracy and in how costly they are to assess. As an example, we consider a mate-choice situation where females choose between males of differing quality. Our model predicts the following: (i) females should become less choosy as the cost of finding new males increases; (ii) females should prioritize cues differently depending on how choosy they are; (iii) females may sometimes prioritize less accurate cues; and (iv) which cues are most important depends on the abundance of desirable mates. These predictions are testable in mate-choice experiments where the costs of choice can be manipulated. Our findings are applicable to other discrimination tasks besides mate choice, for example a predator's choice between palatable and unpalatable prey, or an altruist's choice between kin and non-kin. PMID:12908986

The Geomagnetic Field Is a Compass Cue in Cataglyphis Ant Navigation.

PubMed

Fleischmann, Pauline Nikola; Grob, Robin; Müller, Valentin Leander; Wehner, Rüdiger; Rössler, Wolfgang

2018-05-07

Desert ants (Cataglyphis) are famous insect navigators. During their foraging lives, the ants leave their underground colonies for long distances and return to their starting point with fair accuracy [1, 2]. Their incessantly running path integrator provides them with a continually updated home vector [3-5]. Directional input to their path integrator is provided by a visual compass based on celestial cues [6, 7]. However, as path integration is prone to cumulative errors, the ants additionally employ landmark guidance routines [8-11]. At the start of their foraging lives, they acquire the necessary landmark information by performing well-structured learning walks [12, 13], including turns about their vertical body axes [14]. When Cataglyphis noda performs these pirouettes, it always gazes at the nest entrance during the longest of several short stopping phases [14]. As the small nest entrance is not visible, the ants can adjust their gaze direction only by reading out their path integrator. However, recent experiments have shown that, for adjusting the goal-centered gaze directions during learning walks, skylight cues are not required [15]. A most promising remaining compass cue is the geomagnetic field, which is used for orientation in one way or the other by a variety of animal species [16-25]. Here, we show that the gaze directions during the look-back-to-the-nest behavior change in a predictable way to alterations of the horizontal component of the magnetic field. This is the first demonstration that, in insects, a geomagnetic compass cue is both necessary and sufficient for accomplishing a well-defined navigational task. Copyright © 2018 Elsevier Ltd. All rights reserved.

Seeing is believing: information content and behavioural response to visual and chemical cues

PubMed Central

Gonzálvez, Francisco G.; Rodríguez-Gironés, Miguel A.

2013-01-01

Predator avoidance and foraging often pose conflicting demands. Animals can decrease mortality risk searching for predators, but searching decreases foraging time and hence intake. We used this principle to investigate how prey should use information to detect, assess and respond to predation risk from an optimal foraging perspective. A mathematical model showed that solitary bees should increase flower examination time in response to predator cues and that the rate of false alarms should be negatively correlated with the relative value of the flower explored. The predatory ant, Oecophylla smaragdina, and the harmless ant, Polyrhachis dives, differ in the profile of volatiles they emit and in their visual appearance. As predicted, the solitary bee Nomia strigata spent more time examining virgin flowers in presence of predator cues than in their absence. Furthermore, the proportion of flowers rejected decreased from morning to noon, as the relative value of virgin flowers increased. In addition, bees responded differently to visual and chemical cues. While chemical cues induced bees to search around flowers, bees detecting visual cues hovered in front of them. These strategies may allow prey to identify the nature of visual cues and to locate the source of chemical cues. PMID:23698013

Motion Cueing Algorithm Development: New Motion Cueing Program Implementation and Tuning

NASA Technical Reports Server (NTRS)

Houck, Jacob A. (Technical Monitor); Telban, Robert J.; Cardullo, Frank M.; Kelly, Lon C.

2005-01-01

A computer program has been developed for the purpose of driving the NASA Langley Research Center Visual Motion Simulator (VMS). This program includes two new motion cueing algorithms, the optimal algorithm and the nonlinear algorithm. A general description of the program is given along with a description and flowcharts for each cueing algorithm, and also descriptions and flowcharts for subroutines used with the algorithms. Common block variable listings and a program listing are also provided. The new cueing algorithms have a nonlinear gain algorithm implemented that scales each aircraft degree-of-freedom input with a third-order polynomial. A description of the nonlinear gain algorithm is given along with past tuning experience and procedures for tuning the gain coefficient sets for each degree-of-freedom to produce the desired piloted performance. This algorithm tuning will be needed when the nonlinear motion cueing algorithm is implemented on a new motion system in the Cockpit Motion Facility (CMF) at the NASA Langley Research Center.

Gait parameter control timing with dynamic manual contact or visual cues.

PubMed

Rabin, Ely; Shi, Peter; Werner, William

2016-06-01

We investigated the timing of gait parameter changes (stride length, peak toe velocity, and double-, single-support, and complete step duration) to control gait speed. Eleven healthy participants adjusted their gait speed on a treadmill to maintain a constant distance between them and a fore-aft oscillating cue (a place on a conveyor belt surface). The experimental design balanced conditions of cue modality (vision: eyes-open; manual contact: eyes-closed while touching the cue); treadmill speed (0.2, 0.4, 0.85, and 1.3 m/s); and cue motion (none, ±10 cm at 0.09, 0.11, and 0.18 Hz). Correlation analyses revealed a number of temporal relationships between gait parameters and cue speed. The results suggest that neural control ranged from feedforward to feedback. Specifically, step length preceded cue velocity during double-support duration suggesting anticipatory control. Peak toe velocity nearly coincided with its most-correlated cue velocity during single-support duration. The toe-off concluding step and double-support durations followed their most-correlated cue velocity, suggesting feedback control. Cue-tracking accuracy and cue velocity correlations with timing parameters were higher with the manual contact cue than visual cue. The cue/gait timing relationships generalized across cue modalities, albeit with greater delays of step-cycle events relative to manual contact cue velocity. We conclude that individual kinematic parameters of gait are controlled to achieve a desired velocity at different specific times during the gait cycle. The overall timing pattern of instantaneous cue velocities associated with different gait parameters is conserved across cues that afford different performance accuracies. This timing pattern may be temporally shifted to optimize control. Different cue/gait parameter latencies in our nonadaptation paradigm provide general-case evidence of the independent control of gait parameters previously demonstrated in gait adaptation paradigms. Copyright © 2016 the American Physiological Society.

Motion Cueing Algorithm Development: Initial Investigation and Redesign of the Algorithms

NASA Technical Reports Server (NTRS)

Telban, Robert J.; Wu, Weimin; Cardullo, Frank M.; Houck, Jacob A. (Technical Monitor)

2000-01-01

In this project four motion cueing algorithms were initially investigated. The classical algorithm generated results with large distortion and delay and low magnitude. The NASA adaptive algorithm proved to be well tuned with satisfactory performance, while the UTIAS adaptive algorithm produced less desirable results. Modifications were made to the adaptive algorithms to reduce the magnitude of undesirable spikes. The optimal algorithm was found to have the potential for improved performance with further redesign. The center of simulator rotation was redefined. More terms were added to the cost function to enable more tuning flexibility. A new design approach using a Fortran/Matlab/Simulink setup was employed. A new semicircular canals model was incorporated in the algorithm. With these changes results show the optimal algorithm has some advantages over the NASA adaptive algorithm. Two general problems observed in the initial investigation required solutions. A nonlinear gain algorithm was developed that scales the aircraft inputs by a third-order polynomial, maximizing the motion cues while remaining within the operational limits of the motion system. A braking algorithm was developed to bring the simulator to a full stop at its motion limit and later release the brake to follow the cueing algorithm output.

All Cues Are Not Created Equal: The Case for Facilitating the Acquisition of Typical Weighting Strategies in Children With Hearing Loss

PubMed Central

Nittrouer, Susan

2015-01-01

Purpose One task of childhood involves learning to optimally weight acoustic cues in the speech signal in order to recover phonemic categories. This study examined the extent to which spectral degradation, as associated with cochlear implants, might interfere. The 3 goals were to measure, for adults and children, (a) cue weighting with spectrally degraded signals, (b) sensitivity to degraded cues, and (c) word recognition for degraded signals. Method Twenty-three adults and 36 children (10 and 8 years old) labeled spectrally degraded stimuli from /bɑ/-to-/wɑ/ continua varying in formant and amplitude rise time (FRT and ART). They also discriminated degraded stimuli from FRT and ART continua, and recognized words. Results A developmental increase in the weight assigned to FRT in labeling was clearly observed, with a slight decrease in weight assigned to ART. Sensitivity to these degraded cues measured by the discrimination task could not explain variability in cue weighting. FRT cue weighting explained significant variability in word recognition; ART cue weighting did not. Conclusion Spectral degradation affects children more than adults, but that degradation cannot explain the greater diminishment in children's weighting of FRT. It is suggested that auditory training could strengthen the weighting of spectral cues for implant recipients. PMID:25611214

Feature-based attention potentiates recovery of fine direction discrimination in cortically blind patients.

PubMed

Cavanaugh, Matthew R; Barbot, Antoine; Carrasco, Marisa; Huxlin, Krystel R

2017-12-10

Training chronic, cortically-blind (CB) patients on a coarse [left-right] direction discrimination and integration (CDDI) task recovers performance on this task at trained, blind field locations. However, fine direction difference (FDD) thresholds remain elevated at these locations, limiting the usefulness of recovered vision in daily life. Here, we asked if this FDD impairment can be overcome by training CB subjects with endogenous, feature-based attention (FBA) cues. Ten CB subjects were recruited and trained on CDDI and FDD with an FBA cue or FDD with a neutral cue. After completion of each training protocol, FDD thresholds were re-measured with both neutral and FBA cues at trained, blind-field locations and at corresponding, intact-field locations. In intact portions of the visual field, FDD thresholds were lower when tested with FBA than neutral cues. Training subjects in the blind field on the CDDI task improved FDD performance to the point that a threshold could be measured, but these locations remained impaired relative to the intact field. FDD training with neutral cues resulted in better blind field FDD thresholds than CDDI training, but thresholds remained impaired relative to intact field levels, regardless of testing cue condition. Importantly, training FDD in the blind field with FBA lowered FDD thresholds relative to CDDI training, and allowed the blind field to reach thresholds similar to the intact field, even when FBA trained subjects were tested with a neutral rather than FBA cue. Finally, FDD training appeared to also recover normal integration thresholds at trained, blind-field locations, providing an interesting double dissociation with respect to CDDI training. In summary, mechanisms governing FBA appear to function normally in both intact and impaired regions of the visual field following V1 damage. Our results mark the first time that FDD thresholds in CB fields have been seen to reach intact field levels of performance. Moreover, FBA can be leveraged during visual training to recover normal, fine direction discrimination and integration performance at trained, blind-field locations, potentiating visual recovery of more complex and precise aspects of motion perception in cortically-blinded fields. Copyright © 2017 Elsevier Ltd. All rights reserved.

Perceptual integration of acoustic cues to laryngeal contrasts in Korean fricatives.

PubMed

Lee, Sarah; Katz, Jonah

2016-02-01

This paper provides evidence that multiple acoustic cues involving the presence of low-frequency energy integrate in the perception of Korean coronal fricatives. This finding helps explain a surprising asymmetry between the production and perception of these fricatives found in previous studies: lower F0 onset in the following vowel leads to a response bias for plain [s] over fortis [s*], despite the fact that there is no evidence for a corresponding acoustic asymmetry in the production of [s] and [s*]. A fixed classification task using the Garner paradigm provides evidence that low F0 in a following vowel and the presence of voicing during frication perceptually integrate. This suggests that Korean listeners in previous experiments were responding to an "intermediate perceptual property" of stimuli, despite the fact that the individual acoustic components of that property are not all present in typical Korean fricative productions. The finding also broadens empirical support for the general idea of perceptual integration to a language, a different manner of consonant, and a situation where covariance of the acoustic cues under investigation is not generally present in a listener's linguistic input.

Neural dynamics for landmark orientation and angular path integration

PubMed Central

Seelig, Johannes D.; Jayaraman, Vivek

2015-01-01

Summary Many animals navigate using a combination of visual landmarks and path integration. In mammalian brains, head direction cells integrate these two streams of information by representing an animal's heading relative to landmarks, yet maintaining their directional tuning in darkness based on self-motion cues. Here we use two-photon calcium imaging in head-fixed flies walking on a ball in a virtual reality arena to demonstrate that landmark-based orientation and angular path integration are combined in the population responses of neurons whose dendrites tile the ellipsoid body — a toroidal structure in the center of the fly brain. The population encodes the fly's azimuth relative to its environment, tracking visual landmarks when available and relying on self-motion cues in darkness. When both visual and self-motion cues are absent, a representation of the animal's orientation is maintained in this network through persistent activity — a potential substrate for short-term memory. Several features of the population dynamics of these neurons and their circular anatomical arrangement are suggestive of ring attractors — network structures proposed to support the function of navigational brain circuits. PMID:25971509

Reversible Information Flow across the Medial Temporal Lobe: The Hippocampus Links Cortical Modules during Memory Retrieval

PubMed Central

Cooper, Elisa; Henson, Richard N.

2013-01-01

A simple cue can be sufficient to elicit vivid recollection of a past episode. Theoretical models suggest that upon perceiving such a cue, disparate episodic elements held in neocortex are retrieved through hippocampal pattern completion. We tested this fundamental assumption by applying functional magnetic resonance imaging (fMRI) while objects or scenes were used to cue participants' recall of previously paired scenes or objects, respectively. We first demonstrate functional segregation within the medial temporal lobe (MTL), showing domain specificity in perirhinal and parahippocampal cortices (for object-processing vs scene-processing, respectively), but domain generality in the hippocampus (retrieval of both stimulus types). Critically, using fMRI latency analysis and dynamic causal modeling, we go on to demonstrate functional integration between these MTL regions during successful memory retrieval, with reversible signal flow from the cue region to the target region via the hippocampus. This supports the claim that the human hippocampus provides the vital associative link that integrates information held in different parts of cortex. PMID:23986252

Implications of learning theory for developing programs to decrease overeating

PubMed Central

Boutelle, Kerri N.; Bouton, Mark E.

2015-01-01

Childhood obesity is associated with medical and psychological comorbidities, and interventions targeting overeating could be pragmatic and have a significant impact on weight. Calorically dense foods are easily available, variable, and tasty which allows for effective opportunities to learn to associate behaviors and cues in the environment with food through fundamental conditioning processes, resulting in measurable psychological and physiological food cue reactivity in vulnerable children. Basic research suggests that initial learning is difficult to erase, and that it is vulnerable to a number of phenomena that will allow the original learning to re-emerge after it is suppressed or replaced. These processes may help explain why it may be difficult to change food cue reactivity and overeating over the long term. Extinction theory may be used to develop effective cue-exposure treatments to decrease food cue reactivity through inhibitory learning, although these processes are complex and require an integral understanding of the theory and individual differences. Additionally, learning theory can be used to develop other interventions that may prove to be useful. Through an integration of learning theory, basic and translational research, it may be possible to develop interventions that can decrease the urges to overeat, and improve the weight status of children. PMID:25998235

The fMRI BOLD response to unisensory and multisensory smoking cues in nicotine-dependent adults

PubMed Central

Cortese, Bernadette M.; Uhde, Thomas W.; Brady, Kathleen T.; McClernon, F. Joseph; Yang, Qing X.; Collins, Heather R.; LeMatty, Todd; Hartwell, Karen J.

2015-01-01

Given that the vast majority of functional magnetic resonance imaging (fMRI) studies of drug cue reactivity use unisensory visual cues, but that multisensory cues may elicit greater craving-related brain responses, the current study sought to compare the fMRI BOLD response to unisensory visual and multisensory, visual plus odor, smoking cues in 17 nicotine-dependent adult cigarette smokers. Brain activation to smoking-related, compared to neutral, pictures was assessed under cigarette smoke and odorless odor conditions. While smoking pictures elicited a pattern of activation consistent with the addiction literature, the multisensory (odor + picture) smoking cues elicited significantly greater and more widespread activation in mainly frontal and temporal regions. BOLD signal elicited by the multi-sensory, but not unisensory cues, was significantly related to participants’ level of control over craving as well. Results demonstrated that the co-presentation of cigarette smoke odor with smoking-related visual cues, compared to the visual cues alone, elicited greater levels of craving-related brain activation in key regions implicated in reward. These preliminary findings support future research aimed at a better understanding of multisensory integration of drug cues and craving. PMID:26475784

The fMRI BOLD response to unisensory and multisensory smoking cues in nicotine-dependent adults.

PubMed

Cortese, Bernadette M; Uhde, Thomas W; Brady, Kathleen T; McClernon, F Joseph; Yang, Qing X; Collins, Heather R; LeMatty, Todd; Hartwell, Karen J

2015-12-30

Given that the vast majority of functional magnetic resonance imaging (fMRI) studies of drug cue reactivity use unisensory visual cues, but that multisensory cues may elicit greater craving-related brain responses, the current study sought to compare the fMRI BOLD response to unisensory visual and multisensory, visual plus odor, smoking cues in 17 nicotine-dependent adult cigarette smokers. Brain activation to smoking-related, compared to neutral, pictures was assessed under cigarette smoke and odorless odor conditions. While smoking pictures elicited a pattern of activation consistent with the addiction literature, the multisensory (odor+picture) smoking cues elicited significantly greater and more widespread activation in mainly frontal and temporal regions. BOLD signal elicited by the multisensory, but not unisensory cues, was significantly related to participants' level of control over craving as well. Results demonstrated that the co-presentation of cigarette smoke odor with smoking-related visual cues, compared to the visual cues alone, elicited greater levels of craving-related brain activation in key regions implicated in reward. These preliminary findings support future research aimed at a better understanding of multisensory integration of drug cues and craving. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Spectrotemporal weighting of binaural cues: Effects of a diotic interferer on discrimination of dynamic interaural differences

PubMed Central

Bibee, Jacqueline M.; Stecker, G. Christopher

2016-01-01

Spatial judgments are often dominated by low-frequency binaural cues and onset cues when binaural cues vary across the spectrum and duration, respectively, of a brief sound. This study combined these dimensions to assess the spectrotemporal weighting of binaural information. Listeners discriminated target interaural time difference (ITD) and interaural level difference (ILD) carried by the onset, offset, or full duration of a 4-kHz Gabor click train with a 2-ms period in the presence or absence of a diotic 500-Hz interferer tone. ITD and ILD thresholds were significantly elevated by the interferer in all conditions and by a similar amount to previous reports for static cues. Binaural interference was dramatically greater for ITD targets lacking onset cues compared to onset and full-duration conditions. Binaural interference for ILD targets was similar across dynamic-cue conditions. These effects mirror the baseline discriminability of dynamic ITD and ILD cues [Stecker and Brown. (2010). J. Acoust. Soc. Am. 127, 3092–3103], consistent with stronger interference for less-robust/higher-variance cues. The results support the view that binaural cue integration occurs simultaneously across multiple variance-weighted dimensions, including time and frequency. PMID:27794286

Spectrotemporal weighting of binaural cues: Effects of a diotic interferer on discrimination of dynamic interaural differences.

PubMed

Bibee, Jacqueline M; Stecker, G Christopher

2016-10-01

Spatial judgments are often dominated by low-frequency binaural cues and onset cues when binaural cues vary across the spectrum and duration, respectively, of a brief sound. This study combined these dimensions to assess the spectrotemporal weighting of binaural information. Listeners discriminated target interaural time difference (ITD) and interaural level difference (ILD) carried by the onset, offset, or full duration of a 4-kHz Gabor click train with a 2-ms period in the presence or absence of a diotic 500-Hz interferer tone. ITD and ILD thresholds were significantly elevated by the interferer in all conditions and by a similar amount to previous reports for static cues. Binaural interference was dramatically greater for ITD targets lacking onset cues compared to onset and full-duration conditions. Binaural interference for ILD targets was similar across dynamic-cue conditions. These effects mirror the baseline discriminability of dynamic ITD and ILD cues [Stecker and Brown. (2010). J. Acoust. Soc. Am. 127, 3092-3103], consistent with stronger interference for less-robust/higher-variance cues. The results support the view that binaural cue integration occurs simultaneously across multiple variance-weighted dimensions, including time and frequency.

A distinct layer of the medulla integrates sky compass signals in the brain of an insect.

PubMed

el Jundi, Basil; Pfeiffer, Keram; Homberg, Uwe

2011-01-01

Mass migration of desert locusts is a common phenomenon in North Africa and the Middle East but how these insects navigate is still poorly understood. Laboratory studies suggest that locusts are able to exploit the sky polarization pattern as a navigational cue. Like other insects locusts detect polarized light through a specialized dorsal rim area (DRA) of the eye. Polarization signals are transmitted through the optic lobe to the anterior optic tubercle (AOTu) and, finally, to the central complex in the brain. Whereas neurons of the AOTu integrate sky polarization and chromatic cues in a daytime dependent manner, the central complex holds a topographic representation of azimuthal directions suggesting a role as an internal sky compass. To understand further the integration of sky compass cues we studied polarization-sensitive (POL) neurons in the medulla that may be intercalated between DRA photoreceptors and AOTu neurons. Five types of POL-neuron were characterized and four of these in multiple recordings. All neurons had wide arborizations in medulla layer 4 and most, additionally, in the dorsal rim area of the medulla and in the accessory medulla, the presumed circadian clock. The neurons showed type-specific orientational tuning to zenithal polarized light and azimuth tuning to unpolarized green and UV light spots. In contrast to neurons of the AOTu, we found no evidence for color opponency and daytime dependent adjustment of sky compass signals. Therefore, medulla layer 4 is a distinct stage in the integration of sky compass signals that precedes the time-compensated integration of celestial cues in the AOTu.

A Distinct Layer of the Medulla Integrates Sky Compass Signals in the Brain of an Insect

PubMed Central

el Jundi, Basil; Pfeiffer, Keram; Homberg, Uwe

2011-01-01

Mass migration of desert locusts is a common phenomenon in North Africa and the Middle East but how these insects navigate is still poorly understood. Laboratory studies suggest that locusts are able to exploit the sky polarization pattern as a navigational cue. Like other insects locusts detect polarized light through a specialized dorsal rim area (DRA) of the eye. Polarization signals are transmitted through the optic lobe to the anterior optic tubercle (AOTu) and, finally, to the central complex in the brain. Whereas neurons of the AOTu integrate sky polarization and chromatic cues in a daytime dependent manner, the central complex holds a topographic representation of azimuthal directions suggesting a role as an internal sky compass. To understand further the integration of sky compass cues we studied polarization-sensitive (POL) neurons in the medulla that may be intercalated between DRA photoreceptors and AOTu neurons. Five types of POL-neuron were characterized and four of these in multiple recordings. All neurons had wide arborizations in medulla layer 4 and most, additionally, in the dorsal rim area of the medulla and in the accessory medulla, the presumed circadian clock. The neurons showed type-specific orientational tuning to zenithal polarized light and azimuth tuning to unpolarized green and UV light spots. In contrast to neurons of the AOTu, we found no evidence for color opponency and daytime dependent adjustment of sky compass signals. Therefore, medulla layer 4 is a distinct stage in the integration of sky compass signals that precedes the time-compensated integration of celestial cues in the AOTu. PMID:22114712

Anticipatory coarticulation facilitates word recognition in toddlers.

PubMed

Mahr, Tristan; McMillan, Brianna T M; Saffran, Jenny R; Ellis Weismer, Susan; Edwards, Jan

2015-09-01

Children learn from their environments and their caregivers. To capitalize on learning opportunities, young children have to recognize familiar words efficiently by integrating contextual cues across word boundaries. Previous research has shown that adults can use phonetic cues from anticipatory coarticulation during word recognition. We asked whether 18-24 month-olds (n=29) used coarticulatory cues on the word "the" when recognizing the following noun. We performed a looking-while-listening eyetracking experiment to examine word recognition in neutral vs. facilitating coarticulatory conditions. Participants looked to the target image significantly sooner when the determiner contained facilitating coarticulatory cues. These results provide the first evidence that novice word-learners can take advantage of anticipatory sub-phonemic cues during word recognition. Copyright © 2015 Elsevier B.V. All rights reserved.

Floral pathway integrator gene expression mediates gradual transmission of environmental and endogenous cues to flowering time.

PubMed

van Dijk, Aalt D J; Molenaar, Jaap

2017-01-01

The appropriate timing of flowering is crucial for the reproductive success of plants. Hence, intricate genetic networks integrate various environmental and endogenous cues such as temperature or hormonal statues. These signals integrate into a network of floral pathway integrator genes. At a quantitative level, it is currently unclear how the impact of genetic variation in signaling pathways on flowering time is mediated by floral pathway integrator genes. Here, using datasets available from literature, we connect Arabidopsis thaliana flowering time in genetic backgrounds varying in upstream signalling components with the expression levels of floral pathway integrator genes in these genetic backgrounds. Our modelling results indicate that flowering time depends in a quite linear way on expression levels of floral pathway integrator genes. This gradual, proportional response of flowering time to upstream changes enables a gradual adaptation to changing environmental factors such as temperature and light.

Cue Reliability Represented in the Shape of Tuning Curves in the Owl's Sound Localization System

PubMed Central

Fischer, Brian J.; Peña, Jose L.

2016-01-01

Optimal use of sensory information requires that the brain estimates the reliability of sensory cues, but the neural correlate of cue reliability relevant for behavior is not well defined. Here, we addressed this issue by examining how the reliability of spatial cue influences neuronal responses and behavior in the owl's auditory system. We show that the firing rate and spatial selectivity changed with cue reliability due to the mechanisms generating the tuning to the sound localization cue. We found that the correlated variability among neurons strongly depended on the shape of the tuning curves. Finally, we demonstrated that the change in the neurons' selectivity was necessary and sufficient for a network of stochastic neurons to predict behavior when sensory cues were corrupted with noise. This study demonstrates that the shape of tuning curves can stand alone as a coding dimension of environmental statistics. SIGNIFICANCE STATEMENT In natural environments, sensory cues are often corrupted by noise and are therefore unreliable. To make the best decisions, the brain must estimate the degree to which a cue can be trusted. The behaviorally relevant neural correlates of cue reliability are debated. In this study, we used the barn owl's sound localization system to address this question. We demonstrated that the mechanisms that account for spatial selectivity also explained how neural responses changed with degraded signals. This allowed for the neurons' selectivity to capture cue reliability, influencing the population readout commanding the owl's sound-orienting behavior. PMID:26888922

Are face representations depth cue invariant?

PubMed

Dehmoobadsharifabadi, Armita; Farivar, Reza

2016-06-01

The visual system can process three-dimensional depth cues defining surfaces of objects, but it is unclear whether such information contributes to complex object recognition, including face recognition. The processing of different depth cues involves both dorsal and ventral visual pathways. We investigated whether facial surfaces defined by individual depth cues resulted in meaningful face representations-representations that maintain the relationship between the population of faces as defined in a multidimensional face space. We measured face identity aftereffects for facial surfaces defined by individual depth cues (Experiments 1 and 2) and tested whether the aftereffect transfers across depth cues (Experiments 3 and 4). Facial surfaces and their morphs to the average face were defined purely by one of shading, texture, motion, or binocular disparity. We obtained identification thresholds for matched (matched identity between adapting and test stimuli), non-matched (non-matched identity between adapting and test stimuli), and no-adaptation (showing only the test stimuli) conditions for each cue and across different depth cues. We found robust face identity aftereffect in both experiments. Our results suggest that depth cues do contribute to forming meaningful face representations that are depth cue invariant. Depth cue invariance would require integration of information across different areas and different pathways for object recognition, and this in turn has important implications for cortical models of visual object recognition.

Optimizing countershading camouflage.

PubMed

Cuthill, Innes C; Sanghera, N Simon; Penacchio, Olivier; Lovell, Paul George; Ruxton, Graeme D; Harris, Julie M

2016-11-15

Countershading, the widespread tendency of animals to be darker on the side that receives strongest illumination, has classically been explained as an adaptation for camouflage: obliterating cues to 3D shape and enhancing background matching. However, there have only been two quantitative tests of whether the patterns observed in different species match the optimal shading to obliterate 3D cues, and no tests of whether optimal countershading actually improves concealment or survival. We use a mathematical model of the light field to predict the optimal countershading for concealment that is specific to the light environment and then test this prediction with correspondingly patterned model "caterpillars" exposed to avian predation in the field. We show that the optimal countershading is strongly illumination-dependent. A relatively sharp transition in surface patterning from dark to light is only optimal under direct solar illumination; if there is diffuse illumination from cloudy skies or shade, the pattern provides no advantage over homogeneous background-matching coloration. Conversely, a smoother gradation between dark and light is optimal under cloudy skies or shade. The demonstration of these illumination-dependent effects of different countershading patterns on predation risk strongly supports the comparative evidence showing that the type of countershading varies with light environment.

Determinants of cue-elicited craving and physiologic reactivity in methamphetamine-dependent subjects in the laboratory.

PubMed

Tolliver, Bryan K; McRae-Clark, Aimee L; Saladin, Michael; Price, Kimber L; Simpson, Annie N; DeSantis, Stacia M; Baker, Nathaniel L; Brady, Kathleen T

2010-03-01

Craving for methamphetamine is commonly reported by heavy users of the drug and may increase the risk of relapse in newly abstinent individuals. Exposure to methamphetamine-associated cues in the laboratory can elicit measureable craving and autonomic reactivity in some individuals with methamphetamine dependence. In this study, clinical and demographic correlates of methamphetamine craving and the optimal conditions for its measurement in the laboratory are explored. Subjective (craving) and physiologic (heart rate and skin conductance) reactivity to presentation of methamphetamine-associated photo, video, and paraphernalia cues were evaluated in 43 subjects with methamphetamine dependence. Association of cue reactivity with demographic and clinical characteristics including duration, frequency, amount, and recency of methamphetamine use were assessed. Craving was reported by fewer than half of subjects at baseline and by approximately 70% of subjects after methamphetamine cue exposure. Relative to baseline, subjective craving was increased by all three cue modalities to a similar extent. In general, physiological cue reactivity correlated poorly with cue-induced craving. Craving at baseline was strongly predictive of cue-induced craving. Differences in cue-induced craving were not associated with age, sex, education, employment, treatment status, or number of days using methamphetamine in the 60 days prior to study entry. In contrast, the degree of baseline craving was strongly associated with employment status and the number of days using methamphetamine in the past 60 days. Cue-induced craving for methamphetamine may be reliably measured in methamphetamine-dependent individuals in the laboratory. Further studies employing the cue reactivity paradigm in methamphetamine dependence are warranted.

Circadian timed episodic-like memory - a bee knows what to do when, and also where.

PubMed

Pahl, Mario; Zhu, Hong; Pix, Waltraud; Tautz, Juergen; Zhang, Shaowu

2007-10-01

This study investigates how the colour, shape and location of patterns could be memorized within a time frame. Bees were trained to visit two Y-mazes, one of which presented yellow vertical (rewarded) versus horizontal (non-rewarded) gratings at one site in the morning, while another presented blue horizontal (rewarded) versus vertical (non-rewarded) gratings at another site in the afternoon. The bees could perform well in the learning tests and various transfer tests, in which (i) all contextual cues from the learning test were present; (ii) the colour cues of the visual patterns were removed, but the location cue, the orientation of the visual patterns and the temporal cue still existed; (iii) the location cue was removed, but other contextual cues, i.e. the colour and orientation of the visual patterns and the temporal cue still existed; (iv) the location cue and the orientation cue of the visual patterns were removed, but the colour cue and temporal cue still existed; (v) the location cue, and the colour cue of the visual patterns were removed, but the orientation cue and the temporal cue still existed. The results reveal that the honeybee can recall the memory of the correct visual patterns by using spatial and/or temporal information. The relative importance of different contextual cues is compared and discussed. The bees' ability to integrate elements of circadian time, place and visual stimuli is akin to episodic-like memory; we have therefore named this kind of memory circadian timed episodic-like memory.

Multisensory Integration Affects Visuo-Spatial Working Memory

ERIC Educational Resources Information Center

Botta, Fabiano; Santangelo, Valerio; Raffone, Antonino; Sanabria, Daniel; Lupianez, Juan; Belardinelli, Marta Olivetti

2011-01-01

In the present study, we investigate how spatial attention, driven by unisensory and multisensory cues, can bias the access of information into visuo-spatial working memory (VSWM). In a series of four experiments, we compared the effectiveness of spatially-nonpredictive visual, auditory, or audiovisual cues in capturing participants' spatial…

Multimodal stimulation of the Colorado potato beetle: Prevalence of visual over olfactory cues

USDA-ARS?s Scientific Manuscript database

Orientation of insects to host plants and conspecifics is the result of detection and integration of chemical and physical cues present in the environment. Sensory organs have evolved to be sensitive to important signals, providing neural input for higher order processing and behavioral output. He...

CUE (CULTURE, UNDERSTANDING, ENRICHMENT)--SOCIAL STUDIES.

ERIC Educational Resources Information Center

BROWN, ROBERT M.; AND OTHERS

THIS PUBLICATION IS A TEACHING GUIDE TO PROVIDE GUIDANCE FOR INTEGRATING CAREFULLY SELECTED AUDIOVISUAL ITEMS INTO EXISTING NINTH-GRADE CURRICULUMS IN SOCIAL STUDIES. IT IS ONE OF FIVE GUIDES PREPARED FOR USE IN PROJECT CUE. AN EXPERIMENTAL PROGRAM DESIGNED TO INCREASE CULTURAL UNDERSTANDING AND ENRICHMENT IN THE EDUCATIONAL PROGRAMS OF HIGH…

Ventral Pallidum Neurons Encode Incentive Value and Promote Cue-Elicited Instrumental Actions.

PubMed

Richard, Jocelyn M; Ambroggi, Frederic; Janak, Patricia H; Fields, Howard L

2016-06-15

The ventral pallidum (VP) is posited to contribute to reward seeking by conveying upstream signals from the nucleus accumbens (NAc). Yet, very little is known about how VP neuron responses contribute to behavioral responses to incentive cues. Here, we recorded activity of VP neurons in a cue-driven reward-seeking task previously shown to require neural activity in the NAc. We find that VP neurons encode both learned cue value and subsequent reward seeking and that activity in VP neurons is required for robust cue-elicited reward seeking. Surprisingly, the onset of VP neuron responses occurs at a shorter latency than cue-elicited responses in NAc neurons. This suggests that this VP encoding is not a passive response to signals generated in the NAc and that VP neurons integrate sensory and motivation-related information received directly from other mesocorticolimbic inputs. Copyright © 2016 Elsevier Inc. All rights reserved.

State of the art on targeted memory reactivation: Sleep your way to enhanced cognition.

PubMed

Schouten, Daphne I; Pereira, Sofia I R; Tops, Mattie; Louzada, Fernando M

2017-04-01

Targeted memory reactivation is a fairly simple technique that has the potential to influence the course of memory formation through application of cues during sleep. Studies have shown that cueing memory during sleep can lead to either an enhanced or decreased representation of the information encoded in the targeted networks, depending on experimental variations. The effects have been associated with sleep parameters and accompanied by activation of memory related brain areas. The findings suggest a causal role of neuronal replay in memory consolidation and provide evidence for the active system consolidation hypothesis. However, the observed inconsistencies across studies suggest that further research is warranted regarding the underlying neural mechanisms and optimal conditions for the application of targeted memory reactivation. The goal of the present review is to integrate the currently available experimental data and to provide an overview of this technique's limitations and pitfalls, as well as its potential applications in everyday use and clinical treatment. Exploring the open questions herein identified should lead to insight into safer and more effective ways of adjusting memory representations to better suit individual needs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of Electromechanical Stimulation on the Maturation of Myotubes on Aligned Electrospun Fibers

PubMed Central

Liao, I-Chien; Liu, Jason B.; Bursac, Nenad; Leong, Kam W.

2009-01-01

Tissue engineering may provide an alternative to cell injection as a therapeutic solution for myocardial infarction. A tissue-engineered muscle patch may offer better host integration and higher functional performance. This study examined the differentiation of skeletal myoblasts on aligned electrospun polyurethane (PU) fibers and in the presence of electromechanical stimulation. Skeletal myoblasts cultured on aligned PU fibers showed more pronounced elongation, better alignment, higher level of transient receptor potential cation channel-1 (TRPC-1) expression, upregulation of contractile proteins and higher percentage of striated myotubes compared to those cultured on random PU fibers and film. The resulting tissue constructs generated tetanus forces of 1.1 mN with a 10-ms time to tetanus. Additional mechanical, electrical, or synchronized electromechanical stimuli applied to myoblasts cultured on PU fibers increased the percentage of striated myotubes from 70 to 85% under optimal stimulation conditions, which was accompanied by an upregulation of contractile proteins such as α-actinin and myosin heavy chain. In describing how electromechanical cues can be combined with topographical cue, this study helped move towards the goal of generating a biomimetic microenvironment for engineering of functional skeletal muscle. PMID:19774099

The use of phrase-level prosodic information in lexical segmentation: evidence from word-spotting experiments in Korean.

PubMed

Kim, Sahyang; Cho, Taehong

2009-05-01

This study investigated the role of phrase-level prosodic boundary information in word segmentation in Korean with two word-spotting experiments. In experiment 1, it was found that intonational cues alone helped listeners with lexical segmentation. Listeners paid more attention to local intonational cues (...H#L...) across the prosodic boundary than the intonational information within a prosodic phrase. The results imply that intonation patterns with high frequency are used, though not exclusively, in lexical segmentation. In experiment 2, final lengthening was added to see how multiple prosodic cues influence lexical segmentation. The results showed that listeners did not necessarily benefit from the presence of both intonational and final lengthening cues: Their performance was improved only when intonational information contained infrequent tonal patterns for boundary marking, showing only partially cumulative effects of prosodic cues. When the intonational information was optimal (frequent) for boundary marking, however, poorer performance was observed with final lengthening. This is arguably because the phrase-initial segmental allophonic cues for the accentual phrase were not matched with the prosodic cues for the intonational phrase. It is proposed that the asymmetrical use of multiple cues was due to interaction between prosodic and segmental information that are computed in parallel in lexical segmentation.

Touch Precision Modulates Visual Bias.

PubMed

Misceo, Giovanni F; Jones, Maurice D

2018-01-01

The sensory precision hypothesis holds that different seen and felt cues about the size of an object resolve themselves in favor of the more reliable modality. To examine this precision hypothesis, 60 college students were asked to look at one size while manually exploring another unseen size either with their bare fingers or, to lessen the reliability of touch, with their fingers sleeved in rigid tubes. Afterwards, the participants estimated either the seen size or the felt size by finding a match from a visual display of various sizes. Results showed that the seen size biased the estimates of the felt size when the reliability of touch decreased. This finding supports the interaction between touch reliability and visual bias predicted by statistically optimal models of sensory integration.

What versus where: Investigating how autobiographical memory retrieval differs when accessed with thematic versus spatial information.

PubMed

Sheldon, Signy; Chu, Sonja

2017-09-01

Autobiographical memory research has investigated how cueing distinct aspects of a past event can trigger different recollective experiences. This research has stimulated theories about how autobiographical knowledge is accessed and organized. Here, we test the idea that thematic information organizes multiple autobiographical events whereas spatial information organizes individual past episodes by investigating how retrieval guided by these two forms of information differs. We used a novel autobiographical fluency task in which participants accessed multiple memory exemplars to event theme and spatial (location) cues followed by a narrative description task in which they described the memories generated to these cues. Participants recalled significantly more memory exemplars to event theme than to spatial cues; however, spatial cues prompted faster access to past memories. Results from the narrative description task revealed that memories retrieved via event theme cues compared to spatial cues had a higher number of overall details, but those recalled to the spatial cues were recollected with a greater concentration on episodic details than those retrieved via event theme cues. These results provide evidence that thematic information organizes and integrates multiple memories whereas spatial information prompts the retrieval of specific episodic content from a past event.

Frontotemporal oxyhemoglobin dynamics predict performance accuracy of dance simulation gameplay: temporal characteristics of top-down and bottom-up cortical activities.

PubMed

Ono, Yumie; Nomoto, Yasunori; Tanaka, Shohei; Sato, Keisuke; Shimada, Sotaro; Tachibana, Atsumichi; Bronner, Shaw; Noah, J Adam

2014-01-15

We utilized the high temporal resolution of functional near-infrared spectroscopy to explore how sensory input (visual and rhythmic auditory cues) are processed in the cortical areas of multimodal integration to achieve coordinated motor output during unrestricted dance simulation gameplay. Using an open source clone of the dance simulation video game, Dance Dance Revolution, two cortical regions of interest were selected for study, the middle temporal gyrus (MTG) and the frontopolar cortex (FPC). We hypothesized that activity in the FPC would indicate top-down regulatory mechanisms of motor behavior; while that in the MTG would be sustained due to bottom-up integration of visual and auditory cues throughout the task. We also hypothesized that a correlation would exist between behavioral performance and the temporal patterns of the hemodynamic responses in these regions of interest. Results indicated that greater temporal accuracy of dance steps positively correlated with persistent activation of the MTG and with cumulative suppression of the FPC. When auditory cues were eliminated from the simulation, modifications in cortical responses were found depending on the gameplay performance. In the MTG, high-performance players showed an increase but low-performance players displayed a decrease in cumulative amount of the oxygenated hemoglobin response in the no music condition compared to that in the music condition. In the FPC, high-performance players showed relatively small variance in the activity regardless of the presence of auditory cues, while low-performance players showed larger differences in the activity between the no music and music conditions. These results suggest that the MTG plays an important role in the successful integration of visual and rhythmic cues and the FPC may work as top-down control to compensate for insufficient integrative ability of visual and rhythmic cues in the MTG. The relative relationships between these cortical areas indicated high- to low-performance levels when performing cued motor tasks. We propose that changes in these relationships can be monitored to gauge performance increases in motor learning and rehabilitation programs. Copyright © 2013 Elsevier Inc. All rights reserved.

Cue Reliability Represented in the Shape of Tuning Curves in the Owl's Sound Localization System.

PubMed

Cazettes, Fanny; Fischer, Brian J; Peña, Jose L

2016-02-17

Optimal use of sensory information requires that the brain estimates the reliability of sensory cues, but the neural correlate of cue reliability relevant for behavior is not well defined. Here, we addressed this issue by examining how the reliability of spatial cue influences neuronal responses and behavior in the owl's auditory system. We show that the firing rate and spatial selectivity changed with cue reliability due to the mechanisms generating the tuning to the sound localization cue. We found that the correlated variability among neurons strongly depended on the shape of the tuning curves. Finally, we demonstrated that the change in the neurons' selectivity was necessary and sufficient for a network of stochastic neurons to predict behavior when sensory cues were corrupted with noise. This study demonstrates that the shape of tuning curves can stand alone as a coding dimension of environmental statistics. In natural environments, sensory cues are often corrupted by noise and are therefore unreliable. To make the best decisions, the brain must estimate the degree to which a cue can be trusted. The behaviorally relevant neural correlates of cue reliability are debated. In this study, we used the barn owl's sound localization system to address this question. We demonstrated that the mechanisms that account for spatial selectivity also explained how neural responses changed with degraded signals. This allowed for the neurons' selectivity to capture cue reliability, influencing the population readout commanding the owl's sound-orienting behavior. Copyright © 2016 the authors 0270-6474/16/362101-10$15.00/0.

Cognition and balance control: does processing of explicit contextual cues of impending perturbations modulate automatic postural responses?

PubMed

Coelho, Daniel Boari; Teixeira, Luis Augusto

2017-08-01

Processing of predictive contextual cues of an impending perturbation is thought to induce adaptive postural responses. Cueing in previous research has been provided through repeated perturbations with a constant foreperiod. This experimental strategy confounds explicit predictive cueing with adaptation and non-specific properties of temporal cueing. Two experiments were performed to assess those factors separately. To perturb upright balance, the base of support was suddenly displaced backwards in three amplitudes: 5, 10 and 15 cm. In Experiment 1, we tested the effect of cueing the amplitude of the impending postural perturbation by means of visual signals, and the effect of adaptation to repeated exposures by comparing block versus random sequences of perturbation. In Experiment 2, we evaluated separately the effects of cueing the characteristics of an impending balance perturbation and cueing the timing of perturbation onset. Results from Experiment 1 showed that the block sequence of perturbations led to increased stability of automatic postural responses, and modulation of magnitude and onset latency of muscular responses. Results from Experiment 2 showed that only the condition cueing timing of platform translation onset led to increased balance stability and modulation of onset latency of muscular responses. Conversely, cueing platform displacement amplitude failed to induce any effects on automatic postural responses in both experiments. Our findings support the interpretation of improved postural responses via optimized sensorimotor processes, at the same time that cast doubt on the notion that cognitive processing of explicit contextual cues advancing the magnitude of an impending perturbation can preset adaptive postural responses.

Implications of learning theory for developing programs to decrease overeating.

PubMed

Boutelle, Kerri N; Bouton, Mark E

2015-10-01

Childhood obesity is associated with medical and psychological comorbidities, and interventions targeting overeating could be pragmatic and have a significant impact on weight. Calorically dense foods are easily available, variable, and tasty which allows for effective opportunities to learn to associate behaviors and cues in the environment with food through fundamental conditioning processes, resulting in measurable psychological and physiological food cue reactivity in vulnerable children. Basic research suggests that initial learning is difficult to erase, and that it is vulnerable to a number of phenomena that will allow the original learning to re-emerge after it is suppressed or replaced. These processes may help explain why it may be difficult to change food cue reactivity and overeating over the long term. Extinction theory may be used to develop effective cue-exposure treatments to decrease food cue reactivity through inhibitory learning, although these processes are complex and require an integral understanding of the theory and individual differences. Additionally, learning theory can be used to develop other interventions that may prove to be useful. Through an integration of learning theory, basic and translational research, it may be possible to develop interventions that can decrease the urges to overeat, and improve the weight status of children. Copyright © 2015 Elsevier Ltd. All rights reserved.

Habituation of adult sea lamprey repeatedly exposed to damage-released alarm and predator cues

USGS Publications Warehouse

Imre, Istvan; Di Rocco, Richard T.; Brown, Grant E.; Johnson, Nicholas

2016-01-01

Predation is an unforgiving selective pressure affecting the life history, morphology and behaviour of prey organisms. Selection should favour organisms that have the ability to correctly assess the information content of alarm cues. This study investigated whether adult sea lamprey Petromyzon marinus habituate to conspecific damage-released alarm cues (fresh and decayed sea lamprey extract), a heterospecific damage-released alarm cue (white sucker Catostomus commersoniiextract), predator cues (Northern water snake Nerodia sipedon washing, human saliva and 2-phenylethylamine hydrochloride (PEA HCl)) and a conspecific damage-released alarm cue and predator cue combination (fresh sea lamprey extract and human saliva) after they were pre-exposed 4 times or 8 times, respectively, to a given stimulus the previous night. Consistent with our prediction, adult sea lamprey maintained an avoidance response to conspecific damage-released alarm cues (fresh and decayed sea lamprey extract), a predator cue presented at high relative concentration (PEA HCl) and a conspecific damage-released alarm cue and predator cue combination (fresh sea lamprey extract plus human saliva), irrespective of previous exposure level. As expected, adult sea lamprey habituated to a sympatric heterospecific damage-released alarm cue (white sucker extract) and a predator cue presented at lower relative concentration (human saliva). Adult sea lamprey did not show any avoidance of the Northern water snake washing and the Amazon sailfin catfish extract (heterospecific control). This study suggests that conspecific damage-released alarm cues and PEA HCl present the best options as natural repellents in an integrated management program aimed at controlling the abundance of sea lamprey in the Laurentian Great Lakes.

What We Observe Is Biased by What Other People Tell Us: Beliefs about the Reliability of Gaze Behavior Modulate Attentional Orienting to Gaze Cues

PubMed Central

Wiese, Eva; Wykowska, Agnieszka; Müller, Hermann J.

2014-01-01

For effective social interactions with other people, information about the physical environment must be integrated with information about the interaction partner. In order to achieve this, processing of social information is guided by two components: a bottom-up mechanism reflexively triggered by stimulus-related information in the social scene and a top-down mechanism activated by task-related context information. In the present study, we investigated whether these components interact during attentional orienting to gaze direction. In particular, we examined whether the spatial specificity of gaze cueing is modulated by expectations about the reliability of gaze behavior. Expectations were either induced by instruction or could be derived from experience with displayed gaze behavior. Spatially specific cueing effects were observed with highly predictive gaze cues, but also when participants merely believed that actually non-predictive cues were highly predictive. Conversely, cueing effects for the whole gazed-at hemifield were observed with non-predictive gaze cues, and spatially specific cueing effects were attenuated when actually predictive gaze cues were believed to be non-predictive. This pattern indicates that (i) information about cue predictivity gained from sampling gaze behavior across social episodes can be incorporated in the attentional orienting to social cues, and that (ii) beliefs about gaze behavior modulate attentional orienting to gaze direction even when they contradict information available from social episodes. PMID:24722348

Pain in context: Cues predicting a reward decrease fear of movement related pain and avoidance behavior.

PubMed

Claes, Nathalie; Vlaeyen, Johan W S; Crombez, Geert

2016-09-01

Previous research shows that goal-directed behavior might be modulated by cues that predict (dis)similar outcomes. However, the literature investigating this modulation with pain outcomes is scarce. Therefore, this experiment investigated whether environmental cues predicting pain or reward modulate defensive pain responding. Forty-eight healthy participants completed a joystick movement task with two different movement orientations. Performing one movement was associated with a painful stimulus, whereas performance of another movement was associated with reward, i.e. lottery tickets. In a subsequent task, participants learned to associate three different cues withpain, reward, or neither of the two. Next, these cues were integrated in the movement task. This study demonstrates that in general, aversive cues enhance and appetitive cues reduce pain-related fear. Furthermore, we found that incongruence between the outcomes predicted by the movement and the cue results in more oscillatory behavior, i.e., participants were more willing to perform a painful movement when a cue predicting reward was simultaneously presented, and vice versa. Similarly, when given a choice, participants preferred to perform the reward movement, unless there was an incongruence between the outcomes predicted by the movements and cues. Taken together, these results provide experimental evidence that environmental cues are capable of modulating pain-related fear and avoidance behavior. Copyright © 2016 Elsevier Ltd. All rights reserved.

An in flight investigation of pitch rate flight control systems and application of frequency domain and time domain predictive criteria

NASA Technical Reports Server (NTRS)

Berthe, C. J.; Chalk, C. R.; Sarrafian, S.

1984-01-01

The degree of attitude control provided by current integral-proportional pitch rate command-type control systems, while a prerequisite for flared landing, is insufficient for 'Level 1' performance. The pilot requires 'surrogate' feedback cues to precisely control flight path in the landing flare. Monotonic stick forces and pilot station vertical acceleration are important cues which can be provided by means of angle-of-attack and pitch rate feedback in order to achieve conventional short period and phugoid characteristics. Integral-proportional pitch rate flight control systems can be upgraded to Level 1 flared landing performance by means of lead/lag and washout prefilters in the command path. Strong pilot station vertical acceleration cues can provide Level 1 flared landing performance even in the absence of monotonic stick forces.

Cueing listeners to attend to a target talker progressively improves word report as the duration of the cue-target interval lengthens to 2,000 ms.

PubMed

Holmes, Emma; Kitterick, Padraig T; Summerfield, A Quentin

2018-04-25

Endogenous attention is typically studied by presenting instructive cues in advance of a target stimulus array. For endogenous visual attention, task performance improves as the duration of the cue-target interval increases up to 800 ms. Less is known about how endogenous auditory attention unfolds over time or the mechanisms by which an instructive cue presented in advance of an auditory array improves performance. The current experiment used five cue-target intervals (0, 250, 500, 1,000, and 2,000 ms) to compare four hypotheses for how preparatory attention develops over time in a multi-talker listening task. Young adults were cued to attend to a target talker who spoke in a mixture of three talkers. Visual cues indicated the target talker's spatial location or their gender. Participants directed attention to location and gender simultaneously ("objects") at all cue-target intervals. Participants were consistently faster and more accurate at reporting words spoken by the target talker when the cue-target interval was 2,000 ms than 0 ms. In addition, the latency of correct responses progressively shortened as the duration of the cue-target interval increased from 0 to 2,000 ms. These findings suggest that the mechanisms involved in preparatory auditory attention develop gradually over time, taking at least 2,000 ms to reach optimal configuration, yet providing cumulative improvements in speech intelligibility as the duration of the cue-target interval increases from 0 to 2,000 ms. These results demonstrate an improvement in performance for cue-target intervals longer than those that have been reported previously in the visual or auditory modalities.

Integration of multiple cues allows threat-sensitive anti-intraguild predator responses in predatory mites

PubMed Central

Walzer, Andreas; Schausberger, Peter

2013-01-01

Intraguild (IG) prey is commonly confronted with multiple IG predator species. However, the IG predation (IGP) risk for prey is not only dependent on the predator species, but also on inherent (intraspecific) characteristics of a given IG predator such as its life-stage, sex or gravidity and the associated prey needs. Thus, IG prey should have evolved the ability to integrate multiple IG predator cues, which should allow both inter- and intraspecific threat-sensitive anti-predator responses. Using a guild of plant-inhabiting predatory mites sharing spider mites as prey, we evaluated the effects of single and combined cues (eggs and/or chemical traces left by a predator female on the substrate) of the low risk IG predator Neoseiulus californicus and the high risk IG predator Amblyseius andersoni on time, distance and path shape parameters of the larval IG prey Phytoseiulus persimilis. IG prey discriminated between traces of the low and high risk IG predator, with and without additional presence of their eggs, indicating interspecific threat-sensitivity. The behavioural changes were manifest in distance moved, activity and path shape of IG prey. The cue combination of traces and eggs of the IG predators conveyed other information than each cue alone, allowing intraspecific threat-sensitive responses by IG prey apparent in changed velocities and distances moved. We argue that graded responses to single and combined IG predator cues are adaptive due to minimization of acceptance errors in IG prey decision making. PMID:23750040

Implicit affective cues and attentional tuning: an integrative review.

PubMed

Friedman, Ronald S; Förster, Jens

2010-09-01

A large and growing number of studies support the notion that arousing positive emotional states expand, and that arousing negative states constrict, the scope of attention on both the perceptual and conceptual levels. However, these studies have predominantly involved the manipulation or measurement of conscious emotional experiences (e.g., subjective feelings of happiness or anxiety). This raises the question: Do cues that are merely associated with benign versus threatening situations but do not elicit conscious feelings of positive or negative emotional arousal independently expand or contract attentional scope? Integrating theoretical advances in affective neuroscience, positive psychology, and social cognition, the authors propose that rudimentary intero- and exteroceptive stimuli may indeed become associated with the onset of arousing positive or negative emotional states and/or with appraisals that the environment is benign or threatening and thereby come to moderate the scope of attention in the absence of conscious emotional experience. Specifically, implicit "benign situation" cues are posited to broaden, and implicit "threatening situation" cues to narrow, the range of both perceptual and conceptual attentional selection. An extensive array of research findings involving a diverse set of such implicit affective cues (e.g., enactment of approach and avoidance behaviors, incidental exposure to colors signaling safety vs. danger) is marshaled in support of this proposition. Potential alternative explanations for and moderators of these attentional tuning effects, as well as their higher level neuropsychological underpinnings, are also discussed along with prospective extensions to a range of other situational cues and domains of social cognitive processing.

Superior Temporal Activation in Response to Dynamic Audio-Visual Emotional Cues

ERIC Educational Resources Information Center

Robins, Diana L.; Hunyadi, Elinora; Schultz, Robert T.

2009-01-01

Perception of emotion is critical for successful social interaction, yet the neural mechanisms underlying the perception of dynamic, audio-visual emotional cues are poorly understood. Evidence from language and sensory paradigms suggests that the superior temporal sulcus and gyrus (STS/STG) play a key role in the integration of auditory and visual…

INTEGRATION OF STIMULUS CUES BY NORMAL AND MENTALLY RETARDED CHILDREN. FINAL REPORT.

ERIC Educational Resources Information Center

ELAM, CLAUDE B.

TWO EXPERIMENTS WERE CONDUCTED IN ORDER TO OBTAIN A MATHEMATICAL DESCRIPTION OF THE PERCEPTUAL PROCESS BY WHICH NORMAL AND MENTALLY RETARDED SUBJECTS SYNTHESIZE STIMULUS CUES IN PERCEPTUAL IDENTIFICATION. THE INITIAL STUDY EMPLOYED 50 COLLEGE STUDENTS, 34 GRADE SCHOOL STUDENTS, AND 24 MENTALLY RETARDED CHILDREN (AGES 9-16) AS SUBJECTS. THE…

Sensorimotor Adaptation Following Exposure to Ambiguous Inertial Motion Cues

NASA Technical Reports Server (NTRS)

Wood, S. J.; Clement, G. R.; Harm, D L.; Rupert, A. H.; Guedry, F. E.; Reschke, M. F.

2005-01-01

The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. Our general hypothesis is that the central nervous system utilizes both multi-sensory integration and frequency segregation as neural strategies to resolve the ambiguity of tilt and translation stimuli. Movement in an altered gravity environment, such as weightlessness without a stable gravity reference, results in new patterns of sensory cues. For example, the semicircular canals, vision and neck proprioception provide information about head tilt on orbit without the normal otolith head-tilt position that is omnipresent on Earth. Adaptive changes in how inertial cues from the otolith system are integrated with other sensory information lead to perceptual and postural disturbances upon return to Earth s gravity. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of disorientation and tilt-translation disturbances reported by crewmembers during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation during tilt and translation motion.

Sensorimotor Adaptation Following Exposure to Ambiguous Inertial Motion Cues

NASA Technical Reports Server (NTRS)

Wood, S. J.; Clement, G. R.; Harm, D. L.; Rupert, A. H.; Guedry, F. E.; Reschke, M. F.

2005-01-01

The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. Our general hypothesis is that the central nervous system utilizes both multi-sensory integration and frequency segregation as neural strategies to resolve the ambiguity of tilt and translation stimuli. Movement in an altered gravity environment, such as weightlessness without a stable gravity reference, results in new patterns of sensory cues. For example, the semicircular canals, vision and neck proprioception provide information about head tilt on orbit without the normal otolith head-tilt position that is omnipresent on Earth. Adaptive changes in how inertial cues from the otolith system are integrated with other sensory information lead to perceptual and postural disturbances upon return to Earth's gravity. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of disorientation and tilt-translation disturbances reported by crewmembers during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation during tilt and translation motion.

Dopamine, Affordance and Active Inference

PubMed Central

Friston, Karl J.; Shiner, Tamara; FitzGerald, Thomas; Galea, Joseph M.; Adams, Rick; Brown, Harriet; Dolan, Raymond J.; Moran, Rosalyn; Stephan, Klaas Enno; Bestmann, Sven

2012-01-01

The role of dopamine in behaviour and decision-making is often cast in terms of reinforcement learning and optimal decision theory. Here, we present an alternative view that frames the physiology of dopamine in terms of Bayes-optimal behaviour. In this account, dopamine controls the precision or salience of (external or internal) cues that engender action. In other words, dopamine balances bottom-up sensory information and top-down prior beliefs when making hierarchical inferences (predictions) about cues that have affordance. In this paper, we focus on the consequences of changing tonic levels of dopamine firing using simulations of cued sequential movements. Crucially, the predictions driving movements are based upon a hierarchical generative model that infers the context in which movements are made. This means that we can confuse agents by changing the context (order) in which cues are presented. These simulations provide a (Bayes-optimal) model of contextual uncertainty and set switching that can be quantified in terms of behavioural and electrophysiological responses. Furthermore, one can simulate dopaminergic lesions (by changing the precision of prediction errors) to produce pathological behaviours that are reminiscent of those seen in neurological disorders such as Parkinson's disease. We use these simulations to demonstrate how a single functional role for dopamine at the synaptic level can manifest in different ways at the behavioural level. PMID:22241972

Cue-induced Behavioral and Neural Changes among Excessive Internet Gamers and Possible Application of Cue Exposure Therapy to Internet Gaming Disorder

PubMed Central

Zhang, Yongjun; Ndasauka, Yamikani; Hou, Juan; Chen, Jiawen; Yang, Li zhuang; Wang, Ying; Han, Long; Bu, Junjie; Zhang, Peng; Zhou, Yifeng; Zhang, Xiaochu

2016-01-01

Internet gaming disorder (IGD) may lead to many negative consequences in everyday life, yet there is currently no effective treatment for IGD. Cue-reactivity paradigm is commonly used to evaluate craving for substance, food, and gambling; cue exposure therapy (CET) is applied to treating substance use disorders (SUDs) and some other psychological disorders such as pathological gambling (PG). However, no study has explored CET’s application to the treatment of IGD except two articles having implied that cues’ exposure may have therapeutic effect on IGD. This paper reviews studies on cue-induced behavioral and neural changes in excessive Internet gamers, indicating that behavioral and neural mechanisms of IGD mostly overlap with those of SUD. The CET’s effects in the treatment of SUDs and PG are also reviewed. We finally propose an optimized CET paradigm, which future studies should consider and investigate as a probable treatment of IGD. PMID:27242589

Caudal Nucleus Accumbens Core Is Critical in the Regulation of Cue-Elicited Approach-Avoidance Decisions

PubMed Central

Hamel, Laurie; Thangarasa, Tharshika; Samadi, Osai

2017-01-01

The nucleus accumbens (NAc) is thought to be a site of integration of positively and negatively valenced information and action selection. Functional differentiation in valence processing has previously been found along the rostrocaudal axis of the shell region of the NAc in assessments of unconditioned motivation. Given that the core region of the NAc has been implicated in the elicitation of motivated behavior in response to conditioned cues, we sought to assess the role of caudal, intermediate, and rostral sites within this subregion in cue-elicited approach-avoidance decisions. Rats were trained to associate visuo-tactile cues with appetitive, aversive, and neutral outcomes. Following the successful acquisition of the cue-outcome associations, rats received microinfusions of GABAA and GABAB receptor agonists (muscimol/baclofen) or saline into the caudal, intermediate, or rostral NAc core and were then exposed to a superimposition of appetitively and aversively valenced cues versus neutral cues in a “conflict test,” as well as to the appetitive versus neutral cues, and aversive cues versus neutral cues, in separate conditioned preference/avoidance tests. Disruption of activity in the intermediate to caudal parts of the NAc core resulted in a robust avoidance bias in response to motivationally conflicting cues, as well as a potentiated avoidance of aversive cues as compared with control animals, coupled with an attenuated conditioned preference for the appetitive cue. These results suggest that the caudal NAc core may have the capacity to exert bidirectional control over appetitively and aversively motivated responses to valence signals. PMID:28275709

Simple heuristics and rules of thumb: where psychologists and behavioural biologists might meet.

PubMed

Hutchinson, John M C; Gigerenzer, Gerd

2005-05-31

The Centre for Adaptive Behaviour and Cognition (ABC) has hypothesised that much human decision-making can be described by simple algorithmic process models (heuristics). This paper explains this approach and relates it to research in biology on rules of thumb, which we also review. As an example of a simple heuristic, consider the lexicographic strategy of Take The Best for choosing between two alternatives: cues are searched in turn until one discriminates, then search stops and all other cues are ignored. Heuristics consist of building blocks, and building blocks exploit evolved or learned abilities such as recognition memory; it is the complexity of these abilities that allows the heuristics to be simple. Simple heuristics have an advantage in making decisions fast and with little information, and in avoiding overfitting. Furthermore, humans are observed to use simple heuristics. Simulations show that the statistical structures of different environments affect which heuristics perform better, a relationship referred to as ecological rationality. We contrast ecological rationality with the stronger claim of adaptation. Rules of thumb from biology provide clearer examples of adaptation because animals can be studied in the environments in which they evolved. The range of examples is also much more diverse. To investigate them, biologists have sometimes used similar simulation techniques to ABC, but many examples depend on empirically driven approaches. ABC's theoretical framework can be useful in connecting some of these examples, particularly the scattered literature on how information from different cues is integrated. Optimality modelling is usually used to explain less detailed aspects of behaviour but might more often be redirected to investigate rules of thumb.

Differential Sharing of Chemical Cues by Social Parasites Versus Social Mutualists in a Three-Species Symbiosis.

PubMed

Emery, Virginia J; Tsutsui, Neil D

2016-04-01

Chemical recognition systems are crucial for maintaining the unity of social insect colonies. It has been proposed that colonies form a common chemical signature, called the gestalt odor, which is used to distinguish colony members and non-members. This chemical integration is achieved actively through social interactions such as trophallaxis and allogrooming, or passively such as through exposure to common nest material. When colonies are infiltrated by social parasites, the intruders often use some form of chemical mimicry. However, it is not always clear how this chemical mimicry is accomplished. Here, we used a three-species nesting symbiosis to test the differences in chemical integration of mutualistic (parabiotic) and parasitic ant species. We found that the parasite (Solenopsis picea) obtains chemical cues from both of the two parabiotic host ant species. However, the two parabiotic species (Crematogaster levior and Camponotus femoratus) maintain species-specific cues, and do not acquire compounds from the other species. Our findings suggest that there is a fundamental difference in how social mutualists and social parasites use chemicals to integrate themselves into colonies.

Finding flowers in the dark: nectar-feeding bats integrate olfaction and echolocation while foraging for nectar

PubMed Central

Gonzalez-Terrazas, Tania P.; Martel, Carlos; Milet-Pinheiro, Paulo; Ayasse, Manfred; Kalko, Elisabeth K. V.; Tschapka, Marco

2016-01-01

Nectar-feeding bats depend mainly on floral nectar to fulfil their energetic requirements. Chiropterophilous flowers generally present strong floral scents and provide conspicuous acoustic echoes to attract bats. While floral scents are assumed to attract bats over long distances, acoustic properties of flower structures may provide detailed information, thus supporting the localization of a flower at close ranges. So far, to our knowledge, there is no study trying to understand the relative importance as well as the combination of these generally coupled cues for detection (presence) and localization (exact position) of open flowers in nature. For a better comprehension of the significance of olfaction and echolocation in the foraging behaviour of nectar-feeding bats, we conducted two-choice experiments with Leptonycteris yerbabuenae. We tested the bats' behaviour in three experimental scenarios with different cues: (i) olfaction versus echolocation, (ii) echolocation versus echolocation and olfaction, and (iii) olfaction versus echolocation and olfaction. We used the floral scent of the bat-pollinated cactus Pachycereus pringlei as olfactory cue and an acrylic paraboloid as acoustic cue. Additionally, we recorded the echolocation behaviour of the bats and analysed the floral scent of P. pringlei. When decoupled cues were offered, bats displayed no preference in choice for any of the two cues. However, bats reacted first to and chose more often the coupled cues. All bats echolocated continuously and broadcast a long terminal group before a successful visit. The floral scent bouquet of P. pringlei is composed of 20 compounds, some of which (e.g. methyl benzoate) were already reported from chiropterophilous plants. Our investigation demonstrates for the first time to our knowledge, that nectar-feeding bats integrate over different sensory modes for detection and precise localization of open flowers. The combined information from olfactory and acoustic cues allows bats to forage more efficiently. PMID:27853595

Treatment of co-occurring PTSD-AUD: Effects of exposure-based and non-trauma focused psychotherapy on alcohol and trauma cue-reactivity

PubMed Central

Nosen, Elizabeth; Littlefield, Andrew K.; Schumacher, Julie A.; Stasiewicz, Paul R.; Coffey, Scott F.

2014-01-01

Laboratory studies have shown that exposure to trauma memories increases both craving and salivation responses to alcohol cues among individual with co-occurring posttraumatic stress disorder (PTSD) and alcohol dependence (AD). The purpose of the present study was to examine 1) whether this cue reactivity is dampened following exposure-based treatment for PTSD and 2) how changes in reactivity to trauma cues correspond to changes in alcohol cue-reactivity. Adults with current PTSD and AD (N=120) were randomly assigned to 9–12 sessions of either Trauma-focused Exposure Therapy (EXP) for PTSD or Health & Lifestyles (HLS, a non-trauma focused comparison treatment), concurrent with 6-week residential AD treatment-asusual. Participants completed trauma and alcohol cue-reactivity laboratory sessions before and after treatment. Compared to HLS, individuals receiving EXP showed significantly greater reductions in negative affect elicited by trauma cues following treatment. Both treatments demonstrated similar, moderate to large reductions in craving and salivary reactivity over time. Interestingly, latent change in trauma cue-elicited distress over the course of treatment predicted latent change in both trauma cue-elicited alcohol craving and salivation. Overall, findings highlight the utility of integrating trauma-focused therapies like EXP into substance use treatment in the interests of reducing PTSD symptoms and distress associated with trauma cues. PMID:25127178

Integration of visual and motion cues for flight simulator requirements and ride quality investigation

NASA Technical Reports Server (NTRS)

Young, L. R.

1976-01-01

Investigations for the improvement of flight simulators are reported. Topics include: visual cues in landing, comparison of linear and nonlinear washout filters using a model of the vestibular system, and visual vestibular interactions (yaw axis). An abstract is given for a thesis on the applications of human dynamic orientation models to motion simulation.

Effectiveness of external cues to facilitate task performance in people with neurological disorders: a systematic review and meta-analysis.

PubMed

Harrison, Stephanie L; Laver, Kate E; Ninnis, Kayla; Rowett, Cherie; Lannin, Natasha A; Crotty, Maria

2018-03-09

To examine in people with neurological disorders, which method/s of providing external cues to improve task performance are most effective. Medline, EMBASE, and PsycINFO were systematically searched. Two reviewers independently screened, extracted data, and assessed the quality of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Twenty six studies were included. Studies examined a wide-range of cues including visual, tactile, auditory, verbal, and multi-component cues. Cueing (any type) improved walking speed when comparing cues to no cues (mean difference (95% confidence interval): 0.08 m/s (0.06-0.10), I 2  = 68%, low quality of evidence). Remaining evidence was analysed narratively; evidence that cueing improves activity-related outcomes was inconsistent and rated as very low quality. It was not possible to determine which form of cueing may be more effective than others. Providing cues to encourage successful task performance is a core component of rehabilitation, however there is limited evidence on the type of cueing or which tasks benefit most from external cueing. Low-quality evidence suggests there may be a beneficial effect of cueing (any type) on walking speed. Sufficiently powered randomised controlled trials are needed to inform therapists of the most effective cueing strategies to improve activity performance in populations with a neurological disorder. Implications for rehabilitation Providing cues is a core component of rehabilitation and may improve successful task performance and activities in people with neurological conditions including stroke, Parkinson's disease, Alzheimer's disease, traumatic brain injury, and multiple sclerosis, but evidence is limited for most neurological conditions with much research focusing on stroke and Parkinson's disease. Therapists should consider using a range of different types of cues depending on the aims of treatment and the neurological condition. There is currently insufficient evidence to suggest one form of cueing is superior to other forms. Therapists should appreciate that responding optimally to cues may take many sessions to have an effect on activities such as walking. Further studies should be conducted over a longer timeframe to examine the effects of different types of cues towards task performance and activities in people with neurological conditions.

Acetylcholine contributes to the integration of self-movement cues in head direction cells.

PubMed

Yoder, Ryan M; Chan, Jeremy H M; Taube, Jeffrey S

2017-08-01

Acetylcholine contributes to accurate performance on some navigational tasks, but details of its contribution to the underlying brain signals are not fully understood. The medial septal area provides widespread cholinergic input to various brain regions, but selective damage to medial septal cholinergic neurons generally has little effect on landmark-based navigation, or the underlying neural representations of location and directional heading in visual environments. In contrast, the loss of medial septal cholinergic neurons disrupts navigation based on path integration, but no studies have tested whether these path integration deficits are associated with disrupted head direction (HD) cell activity. Therefore, we evaluated HD cell responses to visual cue rotations in a familiar arena, and during navigation between familiar and novel arenas, after muscarinic receptor blockade with systemic atropine. Atropine treatment reduced the peak firing rate of HD cells, but failed to significantly affect other HD cell firing properties. Atropine also failed to significantly disrupt the dominant landmark control of the HD signal, even though we used a procedure that challenged this landmark control. In contrast, atropine disrupted HD cell stability during navigation between familiar and novel arenas, where path integration normally maintains a consistent HD cell signal across arenas. These results suggest that acetylcholine contributes to path integration, in part, by facilitating the use of idiothetic cues to maintain a consistent representation of directional heading. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Optic flow odometry operates independently of stride integration in carried ants.

PubMed

Pfeffer, Sarah E; Wittlinger, Matthias

2016-09-09

Cataglyphis desert ants are impressive navigators. When the foragers roam the desert, they employ path integration. For these ants, distance estimation is one key challenge. Distance information was thought to be provided by optic flow (OF)-that is, image motion experienced during travel-but this idea was abandoned when stride integration was discovered as an odometer mechanism in ants. We show that ants transported by nest mates are capable of measuring travel distance exclusively by the use of OF cues. Furthermore, we demonstrate that the information gained from the optic flowmeter cannot be transferred to the stride integrator. Our results suggest a dual information channel that allows the ants to measure distances by strides and OF cues, although both systems operate independently and in a redundant manner. Copyright © 2016, American Association for the Advancement of Science.

The ventrolateral prefrontal cortex facilitates processing of sentential context to locate referents

PubMed Central

Nozari, Nazbanou; Mirman, Daniel; Thompson-Schill, Sharon L.

2016-01-01

Left ventrolateral prefrontal cortex (VLPFC) has been implicated in both integration and conflict resolution in sentence comprehension. Most evidence in favor of the integration account comes from processing ambiguous or anomalous sentences, which also poses a demand for conflict resolution. In two eye-tracking experiments we studied the role of VLPFC in integration when demands for conflict resolution were minimal. Two closely-matched groups of individuals with chronic post-stroke aphasia were tested: the Anterior group had damage to left VLPFC, whereas the Posterior group had left temporo-parietal damage. In Experiment 1 a semantic cue (e.g., “She will eat the apple”) uniquely marked the target (apple) among three distractors that were incompatible with the verb. In Experiment 2 phonological cues (e.g., “She will see an eagle.” / “She will see a bear.”) uniquely marked the target among three distractors whose onsets were incompatible with the cue (e.g., all consonants when the target started with a vowel). In both experiments, control conditions had a similar format, but contained no semantic or phonological contextual information useful for target integration (e.g., the verb “see”, and the determiner “the”). All individuals in the Anterior group were slower in using both types of contextual information to locate the target than were individuals in the Posterior group. These results suggest a role for VLPFC in integration beyond conflict resolution. We discuss a framework that accommodates both integration and conflict resolution. PMID:27148817

Reduced efficiency of audiovisual integration for nonnative speech.

PubMed

Yi, Han-Gyol; Phelps, Jasmine E B; Smiljanic, Rajka; Chandrasekaran, Bharath

2013-11-01

The role of visual cues in native listeners' perception of speech produced by nonnative speakers has not been extensively studied. Native perception of English sentences produced by native English and Korean speakers in audio-only and audiovisual conditions was examined. Korean speakers were rated as more accented in audiovisual than in the audio-only condition. Visual cues enhanced word intelligibility for native English speech but less so for Korean-accented speech. Reduced intelligibility of Korean-accented audiovisual speech was associated with implicit visual biases, suggesting that listener-related factors partially influence the efficiency of audiovisual integration for nonnative speech perception.

Ecological statistics of Gestalt laws for the perceptual organization of contours.

PubMed

Elder, James H; Goldberg, Richard M

2002-01-01

Although numerous studies have measured the strength of visual grouping cues for controlled psychophysical stimuli, little is known about the statistical utility of these various cues for natural images. In this study, we conducted experiments in which human participants trace perceived contours in natural images. These contours are automatically mapped to sequences of discrete tangent elements detected in the image. By examining relational properties between pairs of successive tangents on these traced curves, and between randomly selected pairs of tangents, we are able to estimate the likelihood distributions required to construct an optimal Bayesian model for contour grouping. We employed this novel methodology to investigate the inferential power of three classical Gestalt cues for contour grouping: proximity, good continuation, and luminance similarity. The study yielded a number of important results: (1) these cues, when appropriately defined, are approximately uncorrelated, suggesting a simple factorial model for statistical inference; (2) moderate image-to-image variation of the statistics indicates the utility of general probabilistic models for perceptual organization; (3) these cues differ greatly in their inferential power, proximity being by far the most powerful; and (4) statistical modeling of the proximity cue indicates a scale-invariant power law in close agreement with prior psychophysics.

Toward semantic-based retrieval of visual information: a model-based approach

NASA Astrophysics Data System (ADS)

Park, Youngchoon; Golshani, Forouzan; Panchanathan, Sethuraman

2002-07-01

This paper center around the problem of automated visual content classification. To enable classification based image or visual object retrieval, we propose a new image representation scheme called visual context descriptor (VCD) that is a multidimensional vector in which each element represents the frequency of a unique visual property of an image or a region. VCD utilizes the predetermined quality dimensions (i.e., types of features and quantization level) and semantic model templates mined in priori. Not only observed visual cues, but also contextually relevant visual features are proportionally incorporated in VCD. Contextual relevance of a visual cue to a semantic class is determined by using correlation analysis of ground truth samples. Such co-occurrence analysis of visual cues requires transformation of a real-valued visual feature vector (e.g., color histogram, Gabor texture, etc.,) into a discrete event (e.g., terms in text). Good-feature to track, rule of thirds, iterative k-means clustering and TSVQ are involved in transformation of feature vectors into unified symbolic representations called visual terms. Similarity-based visual cue frequency estimation is also proposed and used for ensuring the correctness of model learning and matching since sparseness of sample data causes the unstable results of frequency estimation of visual cues. The proposed method naturally allows integration of heterogeneous visual or temporal or spatial cues in a single classification or matching framework, and can be easily integrated into a semantic knowledge base such as thesaurus, and ontology. Robust semantic visual model template creation and object based image retrieval are demonstrated based on the proposed content description scheme.

Alerting prefixes for speech warning messages. [in helicopters

NASA Technical Reports Server (NTRS)

Bucher, N. M.; Voorhees, J. W.; Karl, R. L.; Werner, E.

1984-01-01

A major question posed by the design of an integrated voice information display/warning system for next-generation helicopter cockpits is whether an alerting prefix should precede voice warning messages; if so, the characteristics desirable in such a cue must also be addressed. Attention is presently given to the results of a study which ascertained pilot response time and response accuracy to messages preceded by either neutral cues or the cognitively appropriate semantic cues. Both verbal cues and messages were spoken in direct, phoneme-synthesized speech, and a training manipulation was included to determine the extent to which previous exposure to speech thus produced facilitates these messages' comprehension. Results are discussed in terms of the importance of human factors research in cockpit display design.

Learning grammatical categories from distributional cues: flexible frames for language acquisition.

PubMed

St Clair, Michelle C; Monaghan, Padraic; Christiansen, Morten H

2010-09-01

Numerous distributional cues in the child's environment may potentially assist in language learning, but what cues are useful to the child and when are these cues utilised? We propose that the most useful source of distributional cue is a flexible frame surrounding the word, where the language learner integrates information from the preceding and the succeeding word for grammatical categorisation. In corpus analyses of child-directed speech together with computational models of category acquisition, we show that these flexible frames are computationally advantageous for language learning, as they benefit from the coverage of bigram information across a large proportion of the language environment as well as exploiting the enhanced accuracy of trigram information. Flexible frames are also consistent with the developmental trajectory of children's sensitivity to different sources of distributional information, and they are therefore a useful and usable information source for supporting the acquisition of grammatical categories. 2010 Elsevier B.V. All rights reserved.

MPI CyberMotion Simulator: implementation of a novel motion simulator to investigate multisensory path integration in three dimensions.

PubMed

Barnett-Cowan, Michael; Meilinger, Tobias; Vidal, Manuel; Teufel, Harald; Bülthoff, Heinrich H

2012-05-10

Path integration is a process in which self-motion is integrated over time to obtain an estimate of one's current position relative to a starting point (1). Humans can do path integration based exclusively on visual (2-3), auditory (4), or inertial cues (5). However, with multiple cues present, inertial cues - particularly kinaesthetic - seem to dominate (6-7). In the absence of vision, humans tend to overestimate short distances (<5 m) and turning angles (<30°), but underestimate longer ones (5). Movement through physical space therefore does not seem to be accurately represented by the brain. Extensive work has been done on evaluating path integration in the horizontal plane, but little is known about vertical movement (see (3) for virtual movement from vision alone). One reason for this is that traditional motion simulators have a small range of motion restricted mainly to the horizontal plane. Here we take advantage of a motion simulator (8-9) with a large range of motion to assess whether path integration is similar between horizontal and vertical planes. The relative contributions of inertial and visual cues for path navigation were also assessed. 16 observers sat upright in a seat mounted to the flange of a modified KUKA anthropomorphic robot arm. Sensory information was manipulated by providing visual (optic flow, limited lifetime star field), vestibular-kinaesthetic (passive self motion with eyes closed), or visual and vestibular-kinaesthetic motion cues. Movement trajectories in the horizontal, sagittal and frontal planes consisted of two segment lengths (1st: 0.4 m, 2nd: 1 m; ±0.24 m/s(2) peak acceleration). The angle of the two segments was either 45° or 90°. Observers pointed back to their origin by moving an arrow that was superimposed on an avatar presented on the screen. Observers were more likely to underestimate angle size for movement in the horizontal plane compared to the vertical planes. In the frontal plane observers were more likely to overestimate angle size while there was no such bias in the sagittal plane. Finally, observers responded slower when answering based on vestibular-kinaesthetic information alone. Human path integration based on vestibular-kinaesthetic information alone thus takes longer than when visual information is present. That pointing is consistent with underestimating and overestimating the angle one has moved through in the horizontal and vertical planes respectively, suggests that the neural representation of self-motion through space is non-symmetrical which may relate to the fact that humans experience movement mostly within the horizontal plane.

Using texts in science education: cognitive processes and knowledge representation.

PubMed

van den Broek, Paul

2010-04-23

Texts form a powerful tool in teaching concepts and principles in science. How do readers extract information from a text, and what are the limitations in this process? Central to comprehension of and learning from a text is the construction of a coherent mental representation that integrates the textual information and relevant background knowledge. This representation engenders learning if it expands the reader's existing knowledge base or if it corrects misconceptions in this knowledge base. The Landscape Model captures the reading process and the influences of reader characteristics (such as working-memory capacity, reading goal, prior knowledge, and inferential skills) and text characteristics (such as content/structure of presented information, processing demands, and textual cues). The model suggests factors that can optimize--or jeopardize--learning science from text.

Direction-dependent arm kinematics reveal optimal integration of gravity cues.

PubMed

Gaveau, Jeremie; Berret, Bastien; Angelaki, Dora E; Papaxanthis, Charalambos

2016-11-02

The brain has evolved an internal model of gravity to cope with life in the Earth's gravitational environment. How this internal model benefits the implementation of skilled movement has remained unsolved. One prevailing theory has assumed that this internal model is used to compensate for gravity's mechanical effects on the body, such as to maintain invariant motor trajectories. Alternatively, gravity force could be used purposely and efficiently for the planning and execution of voluntary movements, thereby resulting in direction-depending kinematics. Here we experimentally interrogate these two hypotheses by measuring arm kinematics while varying movement direction in normal and zero-G gravity conditions. By comparing experimental results with model predictions, we show that the brain uses the internal model to implement control policies that take advantage of gravity to minimize movement effort.

Slushy weightings for the optimal pilot model. [considering visual tracking task

NASA Technical Reports Server (NTRS)

Dillow, J. D.; Picha, D. G.; Anderson, R. O.

1975-01-01

A pilot model is described which accounts for the effect of motion cues in a well defined visual tracking task. The effect of visual and motion cues are accounted for in the model in two ways. First, the observation matrix in the pilot model is structured to account for the visual and motion inputs presented to the pilot. Secondly, the weightings in the quadratic cost function associated with the pilot model are modified to account for the pilot's perception of the variables he considers important in the task. Analytic results obtained using the pilot model are compared to experimental results and in general good agreement is demonstrated. The analytic model yields small improvements in tracking performance with the addition of motion cues for easily controlled task dynamics and large improvements in tracking performance with the addition of motion cues for difficult task dynamics.

Analysis procedures and subjective flight results of a simulator validation and cue fidelity experiment

NASA Technical Reports Server (NTRS)

Carr, Peter C.; Mckissick, Burnell T.

1988-01-01

A joint experiment to investigate simulator validation and cue fidelity was conducted by the Dryden Flight Research Facility of NASA Ames Research Center (Ames-Dryden) and NASA Langley Research Center. The primary objective was to validate the use of a closed-loop pilot-vehicle mathematical model as an analytical tool for optimizing the tradeoff between simulator fidelity requirements and simulator cost. The validation process includes comparing model predictions with simulation and flight test results to evaluate various hypotheses for differences in motion and visual cues and information transfer. A group of five pilots flew air-to-air tracking maneuvers in the Langley differential maneuvering simulator and visual motion simulator and in an F-14 aircraft at Ames-Dryden. The simulators used motion and visual cueing devices including a g-seat, a helmet loader, wide field-of-view horizon, and a motion base platform.

Spatial Attention Enhances Perceptual Processing of Single-Element Displays

NASA Technical Reports Server (NTRS)

Bacon, William; Johnston, James C.; Remington, Roger W.; Null, Cynthia H. (Technical Monitor)

1994-01-01

Shiu and Pashler (1993) reported that precueing masked, single-element displays had negligible effects on identification accuracy. They argued that spatial attention does not actually enhance stimulus perceptibility, but only reduces decision noise. Alternatively, such negative results may arise if cues are sub-optimal, or if masks place an insufficient premium on timely deployment of attention. We report results showing that valid cueing enhances processing of even single-element displays. Spatial attention does indeed enhance perceptual processes.

Thalamic and parietal brain morphology predicts auditory category learning.

PubMed

Scharinger, Mathias; Henry, Molly J; Erb, Julia; Meyer, Lars; Obleser, Jonas

2014-01-01

Auditory categorization is a vital skill involving the attribution of meaning to acoustic events, engaging domain-specific (i.e., auditory) as well as domain-general (e.g., executive) brain networks. A listener's ability to categorize novel acoustic stimuli should therefore depend on both, with the domain-general network being particularly relevant for adaptively changing listening strategies and directing attention to relevant acoustic cues. Here we assessed adaptive listening behavior, using complex acoustic stimuli with an initially salient (but later degraded) spectral cue and a secondary, duration cue that remained nondegraded. We employed voxel-based morphometry (VBM) to identify cortical and subcortical brain structures whose individual neuroanatomy predicted task performance and the ability to optimally switch to making use of temporal cues after spectral degradation. Behavioral listening strategies were assessed by logistic regression and revealed mainly strategy switches in the expected direction, with considerable individual differences. Gray-matter probability in the left inferior parietal lobule (BA 40) and left precentral gyrus was predictive of "optimal" strategy switch, while gray-matter probability in thalamic areas, comprising the medial geniculate body, co-varied with overall performance. Taken together, our findings suggest that successful auditory categorization relies on domain-specific neural circuits in the ascending auditory pathway, while adaptive listening behavior depends more on brain structure in parietal cortex, enabling the (re)direction of attention to salient stimulus properties. © 2013 Published by Elsevier Ltd.

The Construct of the Multisensory Temporal Binding Window and its Dysregulation in Developmental Disabilities

PubMed Central

Wallace, Mark T.; Stevenson, Ryan A.

2014-01-01

Behavior, perception and cognition are strongly shaped by the synthesis of information across the different sensory modalities. Such multisensory integration often results in performance and perceptual benefits that reflect the additional information conferred by having cues from multiple senses providing redundant or complementary information. The spatial and temporal relationships of these cues provide powerful statistical information about how these cues should be integrated or “bound” in order to create a unified perceptual representation. Much recent work has examined the temporal factors that are integral in multisensory processing, with many focused on the construct of the multisensory temporal binding window – the epoch of time within which stimuli from different modalities is likely to be integrated and perceptually bound. Emerging evidence suggests that this temporal window is altered in a series of neurodevelopmental disorders, including autism, dyslexia and schizophrenia. In addition to their role in sensory processing, these deficits in multisensory temporal function may play an important role in the perceptual and cognitive weaknesses that characterize these clinical disorders. Within this context, focus on improving the acuity of multisensory temporal function may have important implications for the amelioration of the “higher-order” deficits that serve as the defining features of these disorders. PMID:25128432

Combining sky and earth: desert ants (Melophorus bagoti) show weighted integration of celestial and terrestrial cues.

PubMed

Legge, Eric L G; Wystrach, Antoine; Spetch, Marcia L; Cheng, Ken

2014-12-01

Insects typically use celestial sources of directional information for path integration, and terrestrial panoramic information for view-based navigation. Here we set celestial and terrestrial sources of directional information in conflict for homing desert ants (Melophorus bagoti). In the first experiment, ants learned to navigate out of a round experimental arena with a distinctive artificial panorama. On crucial tests, we rotated the arena to create a conflict between the artificial panorama and celestial information. In a second experiment, ants at a feeder in their natural visually-cluttered habitat were displaced prior to their homing journey so that the dictates of path integration (feeder to nest direction) based on a celestial compass conflicted with the dictates of view-based navigation (release point to nest direction) based on the natural terrestrial panorama. In both experiments, ants generally headed in a direction intermediate to the dictates of celestial and terrestrial information. In the second experiment, the ants put more weight on the terrestrial cues when they provided better directional information. We conclude that desert ants weight and integrate the dictates of celestial and terrestrial information in determining their initial heading, even when the two directional cues are highly discrepant. © 2014. Published by The Company of Biologists Ltd.

Preschoolers' Use of Morphosyntactic Cues to Identify Generic Sentences: Indefinite Singular Noun Phrases, Tense, and Aspect

ERIC Educational Resources Information Center

Cimpian, Andrei; Meltzer, Trent J.; Markman, Ellen M.

2011-01-01

Generic sentences (e.g., "Birds lay eggs") convey generalizations about entire categories and may thus be an important source of knowledge for children. However, these sentences cannot be identified by a simple rule, requiring instead the integration of multiple cues. The present studies focused on 3- to 5-year-olds' (N = 91) use of…

Ambiguous Tilt and Translation Motion Cues after Space Flight and Otolith Assessment during Post-Flight Re-Adaptation

NASA Technical Reports Server (NTRS)

Wood, Scott J.; Clarke, A. H.; Harm, D. L.; Rupert, A. H.; Clement, G. R.

2009-01-01

Adaptive changes during space flight in how the brain integrates vestibular cues with other sensory information can lead to impaired movement coordination, vertigo, spatial disorientation and perceptual illusions following Gtransitions. These studies are designed to examine both the physiological basis and operational implications for disorientation and tilt-translation disturbances following short duration space flights.

Preschoolers Benefit From Visually Salient Speech Cues

PubMed Central

Holt, Rachael Frush

2015-01-01

Purpose This study explored visual speech influence in preschoolers using 3 developmentally appropriate tasks that vary in perceptual difficulty and task demands. They also examined developmental differences in the ability to use visually salient speech cues and visual phonological knowledge. Method Twelve adults and 27 typically developing 3- and 4-year-old children completed 3 audiovisual (AV) speech integration tasks: matching, discrimination, and recognition. The authors compared AV benefit for visually salient and less visually salient speech discrimination contrasts and assessed the visual saliency of consonant confusions in auditory-only and AV word recognition. Results Four-year-olds and adults demonstrated visual influence on all measures. Three-year-olds demonstrated visual influence on speech discrimination and recognition measures. All groups demonstrated greater AV benefit for the visually salient discrimination contrasts. AV recognition benefit in 4-year-olds and adults depended on the visual saliency of speech sounds. Conclusions Preschoolers can demonstrate AV speech integration. Their AV benefit results from efficient use of visually salient speech cues. Four-year-olds, but not 3-year-olds, used visual phonological knowledge to take advantage of visually salient speech cues, suggesting possible developmental differences in the mechanisms of AV benefit. PMID:25322336

Visual cues and listening effort: individual variability.

PubMed

Picou, Erin M; Ricketts, Todd A; Hornsby, Benjamin W Y

2011-10-01

To investigate the effect of visual cues on listening effort as well as whether predictive variables such as working memory capacity (WMC) and lipreading ability affect the magnitude of listening effort. Twenty participants with normal hearing were tested using a paired-associates recall task in 2 conditions (quiet and noise) and 2 presentation modalities (audio only [AO] and auditory-visual [AV]). Signal-to-noise ratios were adjusted to provide matched speech recognition across audio-only and AV noise conditions. Also measured were subjective perceptions of listening effort and 2 predictive variables: (a) lipreading ability and (b) WMC. Objective and subjective results indicated that listening effort increased in the presence of noise, but on average the addition of visual cues did not significantly affect the magnitude of listening effort. Although there was substantial individual variability, on average participants who were better lipreaders or had larger WMCs demonstrated reduced listening effort in noise in AV conditions. Overall, the results support the hypothesis that integrating auditory and visual cues requires cognitive resources in some participants. The data indicate that low lipreading ability or low WMC is associated with relatively effortful integration of auditory and visual information in noise.

Simply criminal: predicting burglars' occupancy decisions with a simple heuristic.

PubMed

Snook, Brent; Dhami, Mandeep K; Kavanagh, Jennifer M

2011-08-01

Rational choice theories of criminal decision making assume that offenders weight and integrate multiple cues when making decisions (i.e., are compensatory). We tested this assumption by comparing how well a compensatory strategy called Franklin's Rule captured burglars' decision policies regarding residence occupancy compared to a non-compensatory strategy (i.e., Matching Heuristic). Forty burglars each decided on the occupancy of 20 randomly selected photographs of residences (for which actual occupancy was known when the photo was taken). Participants also provided open-ended reports on the cues that influenced their decisions in each case, and then rated the importance of eight cues (e.g., deadbolt visible) over all decisions. Burglars predicted occupancy beyond chance levels. The Matching Heuristic was a significantly better predictor of burglars' decisions than Franklin's Rule, and cue use in the Matching Heuristic better corresponded to the cue ecological validities in the environment than cue use in Franklin's Rule. The most important cue in burglars' models was also the most ecologically valid or predictive of actual occupancy (i.e., vehicle present). The majority of burglars correctly identified the most important cue in their models, and the open-ended technique showed greater correspondence between self-reported and captured cue use than the rating over decision technique. Our findings support a limited rationality perspective to understanding criminal decision making, and have implications for crime prevention.

Optimizing virtual reality for all users through gaze-contingent and adaptive focus displays.

PubMed

Padmanaban, Nitish; Konrad, Robert; Stramer, Tal; Cooper, Emily A; Wetzstein, Gordon

2017-02-28

From the desktop to the laptop to the mobile device, personal computing platforms evolve over time. Moving forward, wearable computing is widely expected to be integral to consumer electronics and beyond. The primary interface between a wearable computer and a user is often a near-eye display. However, current generation near-eye displays suffer from multiple limitations: they are unable to provide fully natural visual cues and comfortable viewing experiences for all users. At their core, many of the issues with near-eye displays are caused by limitations in conventional optics. Current displays cannot reproduce the changes in focus that accompany natural vision, and they cannot support users with uncorrected refractive errors. With two prototype near-eye displays, we show how these issues can be overcome using display modes that adapt to the user via computational optics. By using focus-tunable lenses, mechanically actuated displays, and mobile gaze-tracking technology, these displays can be tailored to correct common refractive errors and provide natural focus cues by dynamically updating the system based on where a user looks in a virtual scene. Indeed, the opportunities afforded by recent advances in computational optics open up the possibility of creating a computing platform in which some users may experience better quality vision in the virtual world than in the real one.

Optimizing virtual reality for all users through gaze-contingent and adaptive focus displays

NASA Astrophysics Data System (ADS)

Padmanaban, Nitish; Konrad, Robert; Stramer, Tal; Cooper, Emily A.; Wetzstein, Gordon

2017-02-01

From the desktop to the laptop to the mobile device, personal computing platforms evolve over time. Moving forward, wearable computing is widely expected to be integral to consumer electronics and beyond. The primary interface between a wearable computer and a user is often a near-eye display. However, current generation near-eye displays suffer from multiple limitations: they are unable to provide fully natural visual cues and comfortable viewing experiences for all users. At their core, many of the issues with near-eye displays are caused by limitations in conventional optics. Current displays cannot reproduce the changes in focus that accompany natural vision, and they cannot support users with uncorrected refractive errors. With two prototype near-eye displays, we show how these issues can be overcome using display modes that adapt to the user via computational optics. By using focus-tunable lenses, mechanically actuated displays, and mobile gaze-tracking technology, these displays can be tailored to correct common refractive errors and provide natural focus cues by dynamically updating the system based on where a user looks in a virtual scene. Indeed, the opportunities afforded by recent advances in computational optics open up the possibility of creating a computing platform in which some users may experience better quality vision in the virtual world than in the real one.

Sensorimotor Adaptation Following Exposure to Ambiguous Inertial Motion Cues

NASA Technical Reports Server (NTRS)

Wood, S. J.; Clement, G. R.; Rupert, A. H.; Reschke, M. F.; Harm, D. L.; Guedry, F. E.

2007-01-01

The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. Adaptive changes in how inertial cues from the otolith system are integrated with other sensory information lead to perceptual and postural disturbances upon return to Earth s gravity. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of tilt-translation disturbances during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation during tilt and translation motion.

Slant Perception Under Stereomicroscopy.

PubMed

Horvath, Samantha; Macdonald, Kori; Galeotti, John; Klatzky, Roberta L

2017-11-01

Objective These studies used threshold and slant-matching tasks to assess and quantitatively measure human perception of 3-D planar images viewed through a stereomicroscope. The results are intended for use in developing augmented-reality surgical aids. Background Substantial research demonstrates that slant perception is performed with high accuracy from monocular and binocular cues, but less research concerns the effects of magnification. Viewing through a microscope affects the utility of monocular and stereo slant cues, but its impact is as yet unknown. Method Participants performed in a threshold slant-detection task and matched the slant of a tool to a surface. Different stimuli and monocular versus binocular viewing conditions were implemented to isolate stereo cues alone, stereo with perspective cues, accommodation cue only, and cues intrinsic to optical-coherence-tomography images. Results At magnification of 5x, slant thresholds with stimuli providing stereo cues approximated those reported for direct viewing, about 12°. Most participants (75%) who passed a stereoacuity pretest could match a tool to the slant of a surface viewed with stereo at 5x magnification, with mean compressive error of about 20% for optimized surfaces. Slant matching to optical coherence tomography images of the cornea viewed under the microscope was also demonstrated. Conclusion Despite the distortions and cue loss introduced by viewing under the stereomicroscope, most participants were able to detect and interact with slanted surfaces. Application The experiments demonstrated sensitivity to surface slant that supports the development of augmented-reality systems to aid microscope-aided surgery.

Phasic alertness cues modulate visual processing speed in healthy aging.

PubMed

Haupt, Marleen; Sorg, Christian; Napiórkowski, Natan; Finke, Kathrin

2018-05-31

Warning signals temporarily increase the rate of visual information in younger participants and thus optimize perception in critical situations. It is unclear whether such important preparatory processes are preserved in healthy aging. We parametrically assessed the effects of auditory alertness cues on visual processing speed and their time course using a whole report paradigm based on the computational Theory of Visual Attention. We replicated prior findings of significant alerting benefits in younger adults. In conditions with short cue-target onset asynchronies, this effect was baseline-dependent. As younger participants with high baseline speed did not show a profit, an inverted U-shaped function of phasic alerting and visual processing speed was implied. Older adults also showed a significant cue-induced benefit. Bayesian analyses indicated that the cueing benefit on visual processing speed was comparably strong across age groups. Our results indicate that in aging individuals, comparable to younger ones, perception is active and increased expectancy of the appearance of a relevant stimulus can increase the rate of visual information uptake. Copyright © 2018 Elsevier Inc. All rights reserved.

Algorithm for Simulating Atmospheric Turbulence and Aeroelastic Effects on Simulator Motion Systems

NASA Technical Reports Server (NTRS)

Ercole, Anthony V.; Cardullo, Frank M.; Kelly, Lon C.; Houck, Jacob A.

2012-01-01

Atmospheric turbulence produces high frequency accelerations in aircraft, typically greater than the response to pilot input. Motion system equipped flight simulators must present cues representative of the aircraft response to turbulence in order to maintain the integrity of the simulation. Currently, turbulence motion cueing produced by flight simulator motion systems has been less than satisfactory because the turbulence profiles have been attenuated by the motion cueing algorithms. This report presents a new turbulence motion cueing algorithm, referred to as the augmented turbulence channel. Like the previous turbulence algorithms, the output of the channel only augments the vertical degree of freedom of motion. This algorithm employs a parallel aircraft model and an optional high bandwidth cueing filter. Simulation of aeroelastic effects is also an area where frequency content must be preserved by the cueing algorithm. The current aeroelastic implementation uses a similar secondary channel that supplements the primary motion cue. Two studies were conducted using the NASA Langley Visual Motion Simulator and Cockpit Motion Facility to evaluate the effect of the turbulence channel and aeroelastic model on pilot control input. Results indicate that the pilot is better correlated with the aircraft response, when the augmented channel is in place.

Depth and elaboration of processing in relation to age.

PubMed

Simon, E

1979-03-01

Processing at encoding and retrieval was jointly manipulated, and then the retrieval effectiveness of different cues was directly compared to uncover the relative pattern of deep and elaborate processing in relation to both age and different experimental manipulations. In experiment 1 phonemic and semantic cues were effective retrieval aids for to-be-remembered words in the youngest group; with increasing age, semantic cues decreased in effectiveness more than phonemic cues. These data showed phonemic features to have an importance that is not recognized in the data generated by the typical levels paradigm. When elaboration of the words was induced in Experiment 2 by presenting them in sentences, semantic and context cues were most effective in the youngest group whereas phonemic cues were most effective in the oldest group. Since the pattern of cue effectiveness in the elderly was similar to that in Experiment 1, where the same words were presented alone, it was concluded that aging results in poor elaboration, in particular, in inefficient integration of word events with the context of presentation. These age effects were mimicked in young subjects in Experiment 3 by experimentally restricting encoding time. The present approach uses somewhat modified views of depth and elaboration.

Low-level visual attention and its relation to joint attention in autism spectrum disorder.

PubMed

Jaworski, Jessica L Bean; Eigsti, Inge-Marie

2017-04-01

Visual attention is integral to social interaction and is a critical building block for development in other domains (e.g., language). Furthermore, atypical attention (especially joint attention) is one of the earliest markers of autism spectrum disorder (ASD). The current study assesses low-level visual attention and its relation to social attentional processing in youth with ASD and typically developing (TD) youth, aged 7 to 18 years. The findings indicate difficulty overriding incorrect attentional cues in ASD, particularly with non-social (arrow) cues relative to social (face) cues. The findings also show reduced competition in ASD from cues that remain on-screen. Furthermore, social attention, autism severity, and age were all predictors of competing cue processing. The results suggest that individuals with ASD may be biased towards speeded rather than accurate responding, and further, that reduced engagement with visual information may impede responses to visual attentional cues. Once attention is engaged, individuals with ASD appear to interpret directional cues as meaningful. These findings from a controlled, experimental paradigm were mirrored in results from an ecologically valid measure of social attention. Attentional difficulties may be exacerbated during the complex and dynamic experience of actual social interaction. Implications for intervention are discussed.

Conspecific and Heterospecific Cues Override Resource Quality to Influence Offspring Production

PubMed Central

Miller, Christine W.; Fletcher, Robert J.; Gillespie, Stephanie R.

2013-01-01

Animals live in an uncertain world. To reduce uncertainty, animals use cues that can encode diverse information regarding habitat quality, including both non-social and social cues. While it is increasingly appreciated that the sources of potential information are vast, our understanding of how individuals integrate different types of cues to guide decision-making remains limited. We experimentally manipulated both resource quality (presence/absence of cactus fruit) and social cues (conspecific juveniles, heterospecific juveniles, no juveniles) for a cactus-feeding insect, Narnia femorata (Hemiptera: Coreidae), to ask how individuals responded to resource quality in the presence or absence of social cues. Cactus with fruit is a high-quality environment for juvenile development, and indeed we found that females laid 56% more eggs when cactus fruit was present versus when it was absent. However, when conspecific or heterospecific juveniles were present, the effects of resource quality on egg numbers vanished. Overall, N . femorata laid approximately twice as many eggs in the presence of heterospecifics than alone or in the presence of conspecifics. Our results suggest that the presence of both conspecific and heterospecific social cues can disrupt responses of individuals to environmental gradients in resource quality. PMID:23861984

Perception of health from facial cues

PubMed Central

Henderson, Audrey J.; Holzleitner, Iris J.; Talamas, Sean N.

2016-01-01

Impressions of health are integral to social interactions, yet poorly understood. A review of the literature reveals multiple facial characteristics that potentially act as cues to health judgements. The cues vary in their stability across time: structural shape cues including symmetry and sexual dimorphism alter slowly across the lifespan and have been found to have weak links to actual health, but show inconsistent effects on perceived health. Facial adiposity changes over a medium time course and is associated with both perceived and actual health. Skin colour alters over a short time and has strong effects on perceived health, yet links to health outcomes have barely been evaluated. Reviewing suggested an additional influence of demeanour as a perceptual cue to health. We, therefore, investigated the association of health judgements with multiple facial cues measured objectively from two-dimensional and three-dimensional facial images. We found evidence for independent contributions of face shape and skin colour cues to perceived health. Our empirical findings: (i) reinforce the role of skin yellowness; (ii) demonstrate the utility of global face shape measures of adiposity; and (iii) emphasize the role of affect in facial images with nominally neutral expression in impressions of health. PMID:27069057

Differential processing of binocular and monocular gloss cues in human visual cortex

PubMed Central

Di Luca, Massimiliano; Ban, Hiroshi; Muryy, Alexander; Fleming, Roland W.

2016-01-01

The visual impression of an object's surface reflectance (“gloss”) relies on a range of visual cues, both monocular and binocular. Whereas previous imaging work has identified processing within ventral visual areas as important for monocular cues, little is known about cortical areas involved in processing binocular cues. Here, we used human functional MRI (fMRI) to test for brain areas selectively involved in the processing of binocular cues. We manipulated stereoscopic information to create four conditions that differed in their disparity structure and in the impression of surface gloss that they evoked. We performed multivoxel pattern analysis to find areas whose fMRI responses allow classes of stimuli to be distinguished based on their depth structure vs. material appearance. We show that higher dorsal areas play a role in processing binocular gloss information, in addition to known ventral areas involved in material processing, with ventral area lateral occipital responding to both object shape and surface material properties. Moreover, we tested for similarities between the representation of gloss from binocular cues and monocular cues. Specifically, we tested for transfer in the decoding performance of an algorithm trained on glossy vs. matte objects defined by either binocular or by monocular cues. We found transfer effects from monocular to binocular cues in dorsal visual area V3B/kinetic occipital (KO), suggesting a shared representation of the two cues in this area. These results indicate the involvement of mid- to high-level visual circuitry in the estimation of surface material properties, with V3B/KO potentially playing a role in integrating monocular and binocular cues. PMID:26912596

Targeting extinction and reconsolidation mechanisms to combat the impact of drug cues on addiction.

PubMed

Taylor, Jane R; Olausson, Peter; Quinn, Jennifer J; Torregrossa, Mary M

2009-01-01

Drug addiction is a progressive and compulsive disorder, where recurrent craving and relapse to drug-seeking occur even after long periods of abstinence. A major contributing factor to relapse is drug-associated cues. Here we review behavioral and pharmacological studies outlining novel methods of effective and persistent reductions in cue-induced relapse behavior in animal models. We focus on extinction and reconsolidation of cue-drug associations as the memory processes that are the most likely targets for interventions. Extinction involves the formation of new inhibitory memories rather than memory erasure; thus, it should be possible to facilitate the extinction of cue-drug memories to reduce relapse. We propose that context-dependency of extinction might be altered by mnemonic agents, thereby enhancing the efficacy of cue-exposure therapy as treatment strategy. In contrast, interfering with memory reconsolidation processes can disrupt the integrity or strength of specific cue-drug memories. Reconsolidation is argued to be a distinct process that occurs over a brief time period after memory is reactivated/retrieved - when the memory becomes labile and vulnerable to disruption. Reconsolidation is thought to be an independent, perhaps opposing, process to extinction and disruption of reconsolidation has recently been shown to directly affect subsequent cue-drug memory retrieval in an animal model of relapse. We hypothesize that a combined approach aimed at both enhancing the consolidation of cue-drug extinction and interfering with the reconsolidation of cue-drug memories will have a greater potential for persistently inhibiting cue-induced relapse than either treatment alone.

Role of Self-Generated Odor Cues in Contextual Representation

PubMed Central

Aikath, Devdeep; Weible, Aldis P; Rowland, David C; Kentros, Clifford G

2014-01-01

As first demonstrated in the patient H.M., the hippocampus is critically involved in forming episodic memories, the recall of “what” happened “where” and “when.” In rodents, the clearest functional correlate of hippocampal primary neurons is the place field: a cell fires predominantly when the animal is in a specific part of the environment, typically defined relative to the available visuospatial cues. However, rodents have relatively poor visual acuity. Furthermore, they are highly adept at navigating in total darkness. This raises the question of how other sensory modalities might contribute to a hippocampal representation of an environment. Rodents have a highly developed olfactory system, suggesting that cues such as odor trails may be important. To test this, we familiarized mice to a visually cued environment over a number of days while maintaining odor cues. During familiarization, self-generated odor cues unique to each animal were collected by re-using absorbent paperboard flooring from one session to the next. Visual and odor cues were then put in conflict by counter-rotating the recording arena and the flooring. Perhaps surprisingly, place fields seemed to follow the visual cue rotation exclusively, raising the question of whether olfactory cues have any influence at all on a hippocampal spatial representation. However, subsequent removal of the familiar, self-generated odor cues severely disrupted both long-term stability and rotation to visual cues in a novel environment. Our data suggest that odor cues, in the absence of additional rule learning, do not provide a discriminative spatial signal that anchors place fields. Such cues do, however, become integral to the context over time and exert a powerful influence on the stability of its hippocampal representation. © 2014 The Authors. Hippocampus Published by Wiley Periodicals, Inc. PMID:24753119

Plasticity of Fear and Safety Neurons of the Amygdala in Response to Fear Extinction

PubMed Central

Sangha, Susan

2015-01-01

Fear inhibition learning induces plasticity and remodeling of circuits within the amygdala. Most studies examine these changes in nondiscriminative fear conditioning paradigms. Using a discriminative fear, safety, and reward conditioning task, Sangha et al. (2013) have previously reported several neural microcircuits within the basal amygdala (BA) which discriminate among these cues, including a subpopulation of neurons responding selectively to a safety cue and not a fear cue. Here, the hypothesis that these “safety” neurons isolated during discriminative conditioning are biased to become fear cue responsive as a result of extinction, when fear behavior diminishes, was tested. Although 41% of “safety” neurons became fear cue responsive as a result of extinction, the data revealed that there was no bias for these neurons to become preferentially responsive during fear extinction compared to the other identified subgroups. In addition to the plasticity seen in the “safety” neurons, 44% of neurons unresponsive to either the fear cue or safety cue during discriminative conditioning became fear cue responsive during extinction. Together these emergent responses to the fear cue as a result of extinction support the hypothesis that new learning underlies extinction. In contrast, 47% of neurons responsive to the fear cue during discriminative conditioning became unresponsive to the fear cue during extinction. These findings are consistent with a suppression of neural responding mediated by inhibitory learning, or, potentially, by direct unlearning. Together, the data support extinction as an active process involving both gains and losses of responses to the fear cue and suggests the final output of the integrated BA circuit in influencing fear behavior is a balance of excitation and inhibition, and perhaps reversal of learning-induced changes. PMID:26733838

Tactile modulation of hippocampal place fields.

PubMed

Gener, Thomas; Perez-Mendez, Lorena; Sanchez-Vives, Maria V

2013-12-01

Neural correlates of spatial representation can be found in the activity of the hippocampal place cells. These neurons are characterized by firing whenever the animal is located in a particular area of the space, the place field. Place fields are modulated by sensory cues, such as visual, auditory, or olfactory cues, being the influence of visual inputs the most thoroughly studied. Tactile information gathered by the whiskers has a prominent representation in the rat cerebral cortex. However, the influence of whisker-detected tactile cues on place fields remains an open question. Here we studied place fields in an enriched tactile environment where the remaining sensory cues were occluded. First, place cells were recorded before and after blockade of tactile transmission by means of lidocaine applied on the whisker pad. Following tactile deprivation, the majority of place cells decreased their firing rate and their place fields expanded. We next rotated the tactile cues and 90% of place fields rotated with them. Our results demonstrate that tactile information is integrated into place cells at least in a tactile-enriched arena and when other sensory cues are not available. Copyright © 2013 Wiley Periodicals, Inc.

Developmental prosopagnosia and super-recognition: no special role for surface reflectance processing

PubMed Central

Russell, Richard; Chatterjee, Garga; Nakayama, Ken

2011-01-01

Face recognition by normal subjects depends in roughly equal proportions on shape and surface reflectance cues, while object recognition depends predominantly on shape cues. It is possible that developmental prosopagnosics are deficient not in their ability to recognize faces per se, but rather in their ability to use reflectance cues. Similarly, super-recognizers’ exceptional ability with face recognition may be a result of superior surface reflectance perception and memory. We tested this possibility by administering tests of face perception and face recognition in which only shape or reflectance cues are available to developmental prosopagnosics, super-recognizers, and control subjects. Face recognition ability and the relative use of shape and pigmentation were unrelated in all the tests. Subjects who were better at using shape or reflectance cues were also better at using the other type of cue. These results do not support the proposal that variation in surface reflectance perception ability is the underlying cause of variation in face recognition ability. Instead, these findings support the idea that face recognition ability is related to neural circuits using representations that integrate shape and pigmentation information. PMID:22192636

Deciding with the eye: how the visually manipulated accessibility of information in memory influences decision behavior.

PubMed

Platzer, Christine; Bröder, Arndt; Heck, Daniel W

2014-05-01

Decision situations are typically characterized by uncertainty: Individuals do not know the values of different options on a criterion dimension. For example, consumers do not know which is the healthiest of several products. To make a decision, individuals can use information about cues that are probabilistically related to the criterion dimension, such as sugar content or the concentration of natural vitamins. In two experiments, we investigated how the accessibility of cue information in memory affects which decision strategy individuals rely on. The accessibility of cue information was manipulated by means of a newly developed paradigm, the spatial-memory-cueing paradigm, which is based on a combination of the looking-at-nothing phenomenon and the spatial-cueing paradigm. The results indicated that people use different decision strategies, depending on the validity of easily accessible information. If the easily accessible information is valid, people stop information search and decide according to a simple take-the-best heuristic. If, however, information that comes to mind easily has a low predictive validity, people are more likely to integrate all available cue information in a compensatory manner.

Salient regions detection using convolutional neural networks and color volume

NASA Astrophysics Data System (ADS)

Liu, Guang-Hai; Hou, Yingkun

2018-03-01

Convolutional neural network is an important technique in machine learning, pattern recognition and image processing. In order to reduce the computational burden and extend the classical LeNet-5 model to the field of saliency detection, we propose a simple and novel computing model based on LeNet-5 network. In the proposed model, hue, saturation and intensity are utilized to extract depth cues, and then we integrate depth cues and color volume to saliency detection following the basic structure of the feature integration theory. Experimental results show that the proposed computing model outperforms some existing state-of-the-art methods on MSRA1000 and ECSSD datasets.

Feature Integration and Task Switching: Diminished Switch Costs after Controlling for Stimulus, Response, and Cue Repetitions

PubMed Central

Schmidt, James R.; Liefooghe, Baptist

2016-01-01

This report presents data from two versions of the task switching procedure in which the separate influence of stimulus repetitions, response key repetitions, conceptual response repetitions, cue repetitions, task repetitions, and congruency are considered. Experiment 1 used a simple alternating runs procedure with parity judgments of digits and consonant/vowel decisions of letters as the two tasks. Results revealed sizable effects of stimulus and response repetitions, and controlling for these effects reduced the switch cost. Experiment 2 was a cued version of the task switch paradigm with parity and magnitude judgments of digits as the two tasks. Results again revealed large effects of stimulus and response repetitions, in addition to cue repetition effects. Controlling for these effects again reduced the switch cost. Congruency did not interact with our novel “unbiased” measure of switch costs. We discuss how the task switch paradigm might be thought of as a more complex version of the feature integration paradigm and propose an episodic learning account of the effect. We further consider to what extent appeals to higher-order control processes might be unnecessary and propose that controls for feature integration biases should be standard practice in task switching experiments. PMID:26964102

Interactions of the polarization and the sun compass in path integration of desert ants.

PubMed

Lebhardt, Fleur; Ronacher, Bernhard

2014-08-01

Desert ants, Cataglyphis fortis, perform large-scale foraging trips in their featureless habitat using path integration as their main navigation tool. To determine their walking direction they use primarily celestial cues, the sky's polarization pattern and the sun position. To examine the relative importance of these two celestial cues, we performed cue conflict experiments. We manipulated the polarization pattern experienced by the ants during their outbound foraging excursions, reducing it to a single electric field (e-)vector direction with a linear polarization filter. The simultaneous view of the sun created situations in which the directional information of the sun and the polarization compass disagreed. The heading directions of the homebound runs recorded on a test field with full view of the natural sky demonstrate that none of both compasses completely dominated over the other. Rather the ants seemed to compute an intermediate homing direction to which both compass systems contributed roughly equally. Direct sunlight and polarized light are detected in different regions of the ant's compound eye, suggesting two separate pathways for obtaining directional information. In the experimental paradigm applied here, these two pathways seem to feed into the path integrator with similar weights.

Genetic and physiological bases for phenological responses to current and predicted climates

PubMed Central

Wilczek, A. M.; Burghardt, L. T.; Cobb, A. R.; Cooper, M. D.; Welch, S. M.; Schmitt, J.

2010-01-01

We are now reaching the stage at which specific genetic factors with known physiological effects can be tied directly and quantitatively to variation in phenology. With such a mechanistic understanding, scientists can better predict phenological responses to novel seasonal climates. Using the widespread model species Arabidopsis thaliana, we explore how variation in different genetic pathways can be linked to phenology and life-history variation across geographical regions and seasons. We show that the expression of phenological traits including flowering depends critically on the growth season, and we outline an integrated life-history approach to phenology in which the timing of later life-history events can be contingent on the environmental cues regulating earlier life stages. As flowering time in many plants is determined by the integration of multiple environmentally sensitive gene pathways, the novel combinations of important seasonal cues in projected future climates will alter how phenology responds to variation in the flowering time gene network with important consequences for plant life history. We discuss how phenology models in other systems—both natural and agricultural—could employ a similar framework to explore the potential contribution of genetic variation to the physiological integration of cues determining phenology. PMID:20819808

How females of chirping and trilling field crickets integrate the 'what' and 'where' of male acoustic signals during decision making.

PubMed

Gabel, Eileen; Gray, David A; Matthias Hennig, R

2016-11-01

In crickets acoustic communication serves mate selection. Female crickets have to perceive and integrate male cues relevant for mate choice while confronted with several different signals in an acoustically diverse background. Overall female decisions are based on the attractiveness of the temporal pattern (informative about the 'what') and on signal intensity (informative about the 'where') of male calling songs. Here, we investigated how the relevant cues for mate choice are integrated during the decision process by females of five different species of chirping and trilling field crickets. Using a behavioral design, female preferences in no-choice and choice situations for male calling songs differing in pulse rate, modulation depth, intensities, chirp/trill arrangements and temporal shifts were examined. Sensory processing underlying decisions in female field crickets is rather similar as combined evidence suggested that incoming song patterns were analyzed separately by bilaterally paired networks for pattern attractiveness and pattern intensity. A downstream gain control mechanism leads to a weighting of the intensity cue by pattern attractiveness. While remarkable differences between species were observed with respect to specific processing steps, closely related species exhibited more similar preferences than did more distantly related species.

Current Technologies Based on the Knowledge of the Stem Cells Microenvironments.

PubMed

Mawad, Damia; Figtree, Gemma; Gentile, Carmine

2017-01-01

The stem cell microenvironment or niche plays a critical role in the regulation of survival, differentiation and behavior of stem cells and their progenies. Recapitulating each aspect of the stem cell niche is therefore essential for their optimal use in in vitro studies and in vivo as future therapeutics in humans. Engineering of optimal conditions for three-dimensional stem cell culture includes multiple transient and dynamic physiological stimuli, such as blood flow and tissue stiffness. Bioprinting and microfluidics technologies, including organs-on-a-chip, are among the most recent approaches utilized to replicate the three-dimensional stem cell niche for human tissue fabrication that allow the integration of multiple levels of tissue complexity, including blood flow. This chapter focuses on the physico-chemical and genetic cues utilized to engineer the stem cell niche and provides an overview on how both bioprinting and microfluidics technologies are improving our knowledge in this field for both disease modeling and tissue regeneration, including drug discovery and toxicity high-throughput assays and stem cell-based therapies in humans.

Synthetic predator cues impair immune function and make the biological pesticide Bti more lethal for vector mosquitoes.

PubMed

Op De Beeck, Lin; Janssens, Lizanne; Stoks, Robby

2016-03-01

The control of vector mosquitoes is one of the biggest challenges facing humankind with the use of chemical pesticides often leading to environmental impact and the evolution of resistance. Although to a lesser extent, this also holds for Bacillus thuringiensis israelensis (Bti), the most widely used biological pesticide to control mosquito populations. This raises the need for the development of integrated pest management strategies that allow the reduction of Bti concentrations without loss of the mosquito control efficiency. To this end, we tested in a laboratory experiment the combined effects of larval exposure to a sublethal Bti concentration and predation risk cues on life history and physiology of larval and adult Culex pipiens mosquitoes. Besides natural predator kairomones and prey alarm cues, we also tested synthetic kairomones of Notonecta predators. Neither Bti nor predation risk cues affected mortality, yet when both stressors were combined mortality increased on average by 133% compared to the treatment with only predation risk cues. This synergistic interaction was also present when Bti was combined with synthetic kairomones. This was further reflected in changes of the composite index of population performance, which suggested lowered per capita growth rates in mosquitoes exposed to Bti but only when Bti was combined with synthetic kairomones. Furthermore, predation risk cues shortened larval development time, reduced mass at metamorphosis in males, and had an immunosuppressive effect in larval and adult mosquitoes which may affect the mosquito vector competence. We provide the first demonstration that synthetic kairomones may generate similar effects on prey as natural kairomones. The identified immunosuppressive effect of synthetic kairomones and the novel lethal synergism type between a biological pesticide and synthetic predator kairomones provide an important proof of principle illustrating the potential of this combination for integrated mosquito control and should in a next step be evaluated under more natural conditions. It may guide novel integrated pest management programs with Bti that incorporate synthetic kairomones and thereby can reduce environmental impact and evolution of resistance creating more efficient and sustainable mosquito control.

Electrophysiological evidence for Audio-visuo-lingual speech integration.

PubMed

Treille, Avril; Vilain, Coriandre; Schwartz, Jean-Luc; Hueber, Thomas; Sato, Marc

2018-01-31

Recent neurophysiological studies demonstrate that audio-visual speech integration partly operates through temporal expectations and speech-specific predictions. From these results, one common view is that the binding of auditory and visual, lipread, speech cues relies on their joint probability and prior associative audio-visual experience. The present EEG study examined whether visual tongue movements integrate with relevant speech sounds, despite little associative audio-visual experience between the two modalities. A second objective was to determine possible similarities and differences of audio-visual speech integration between unusual audio-visuo-lingual and classical audio-visuo-labial modalities. To this aim, participants were presented with auditory, visual, and audio-visual isolated syllables, with the visual presentation related to either a sagittal view of the tongue movements or a facial view of the lip movements of a speaker, with lingual and facial movements previously recorded by an ultrasound imaging system and a video camera. In line with previous EEG studies, our results revealed an amplitude decrease and a latency facilitation of P2 auditory evoked potentials in both audio-visual-lingual and audio-visuo-labial conditions compared to the sum of unimodal conditions. These results argue against the view that auditory and visual speech cues solely integrate based on prior associative audio-visual perceptual experience. Rather, they suggest that dynamic and phonetic informational cues are sharable across sensory modalities, possibly through a cross-modal transfer of implicit articulatory motor knowledge. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trading of dynamic interaural time and level difference cues and its effect on the auditory motion-onset response measured with electroencephalography.

PubMed

Altmann, Christian F; Ueda, Ryuhei; Bucher, Benoit; Furukawa, Shigeto; Ono, Kentaro; Kashino, Makio; Mima, Tatsuya; Fukuyama, Hidenao

2017-10-01

Interaural time (ITD) and level differences (ILD) constitute the two main cues for sound localization in the horizontal plane. Despite extensive research in animal models and humans, the mechanism of how these two cues are integrated into a unified percept is still far from clear. In this study, our aim was to test with human electroencephalography (EEG) whether integration of dynamic ITD and ILD cues is reflected in the so-called motion-onset response (MOR), an evoked potential elicited by moving sound sources. To this end, ITD and ILD trajectories were determined individually by cue trading psychophysics. We then measured EEG while subjects were presented with either static click-trains or click-trains that contained a dynamic portion at the end. The dynamic part was created by combining ITD with ILD either congruently to elicit the percept of a right/leftward moving sound, or incongruently to elicit the percept of a static sound. In two experiments that differed in the method to derive individual dynamic cue trading stimuli, we observed an MOR with at least a change-N1 (cN1) component for both the congruent and incongruent conditions at about 160-190 ms after motion-onset. A significant change-P2 (cP2) component for both the congruent and incongruent ITD/ILD combination was found only in the second experiment peaking at about 250 ms after motion onset. In sum, this study shows that a sound which - by a combination of counter-balanced ITD and ILD cues - induces a static percept can still elicit a motion-onset response, indicative of independent ITD and ILD processing at the level of the MOR - a component that has been proposed to be, at least partly, generated in non-primary auditory cortex. Copyright © 2017 Elsevier Inc. All rights reserved.

A new CAD approach for improving efficacy of cancer screening

NASA Astrophysics Data System (ADS)

Zheng, Bin; Qian, Wei; Li, Lihua; Pu, Jiantao; Kang, Yan; Lure, Fleming; Tan, Maxine; Qiu, Yuchen

2015-03-01

Since performance and clinical utility of current computer-aided detection (CAD) schemes of detecting and classifying soft tissue lesions (e.g., breast masses and lung nodules) is not satisfactory, many researchers in CAD field call for new CAD research ideas and approaches. The purpose of presenting this opinion paper is to share our vision and stimulate more discussions of how to overcome or compensate the limitation of current lesion-detection based CAD schemes in the CAD research community. Since based on our observation that analyzing global image information plays an important role in radiologists' decision making, we hypothesized that using the targeted quantitative image features computed from global images could also provide highly discriminatory power, which are supplementary to the lesion-based information. To test our hypothesis, we recently performed a number of independent studies. Based on our published preliminary study results, we demonstrated that global mammographic image features and background parenchymal enhancement of breast MR images carried useful information to (1) predict near-term breast cancer risk based on negative screening mammograms, (2) distinguish between true- and false-positive recalls in mammography screening examinations, and (3) classify between malignant and benign breast MR examinations. The global case-based CAD scheme only warns a risk level of the cases without cueing a large number of false-positive lesions. It can also be applied to guide lesion-based CAD cueing to reduce false-positives but enhance clinically relevant true-positive cueing. However, before such a new CAD approach is clinically acceptable, more work is needed to optimize not only the scheme performance but also how to integrate with lesion-based CAD schemes in the clinical practice.

Neural tissue engineering options for peripheral nerve regeneration.

PubMed

Gu, Xiaosong; Ding, Fei; Williams, David F

2014-08-01

Tissue engineered nerve grafts (TENGs) have emerged as a potential alternative to autologous nerve grafts, the gold standard for peripheral nerve repair. Typically, TENGs are composed of a biomaterial-based template that incorporates biochemical cues. A number of TENGs have been used experimentally to bridge long peripheral nerve gaps in various animal models, where the desired outcome is nerve tissue regeneration and functional recovery. So far, the translation of TENGs to the clinic for use in humans has met with a certain degree of success. In order to optimize the TENG design and further approach the matching of TENGs with autologous nerve grafts, many new cues, beyond the traditional ones, will have to be integrated into TENGs. Furthermore, there is a strong requirement for monitoring the real-time dynamic information related to the construction of TENGs. The aim of this opinion paper is to specifically and critically describe the latest advances in the field of neural tissue engineering for peripheral nerve regeneration. Here we delineate new attempts in the design of template (or scaffold) materials, especially in the context of biocompatibility, the choice and handling of support cells, and growth factor release systems. We further discuss the significance of RNAi for peripheral nerve regeneration, anticipate the potential application of RNAi reagents for TENGs, and speculate on the possible contributions of additional elements, including angiogenesis, electrical stimulation, molecular inflammatory mediators, bioactive peptides, antioxidant reagents, and cultured biological constructs, to TENGs. Finally, we consider that a diverse array of physicochemical and biological cues must be orchestrated within a TENG to create a self-consistent coordinated system with a close proximity to the regenerative microenvironment of the peripheral nervous system. Copyright © 2014 Elsevier Ltd. All rights reserved.

White matter fiber compromise contributes differentially to attention and emotion processing impairment in alcoholism, HIV-infection, and their comorbidity.

PubMed

Schulte, T; Müller-Oehring, E M; Sullivan, E V; Pfefferbaum, A

2012-10-01

Alcoholism (ALC) and HIV-1 infection (HIV) each affects emotional and attentional processes and integrity of brain white matter fibers likely contributing to functional compromise. The highly prevalent ALC+HIV comorbidity may exacerbate compromise. We used diffusion tensor imaging (DTI) and an emotional Stroop Match-to-Sample task in 19 ALC, 16 HIV, 15 ALC+HIV, and 15 control participants to investigate whether disruption of fiber system integrity accounts for compromised attentional and emotional processing. The task required matching a cue color to that of an emotional word with faces appearing between the color cue and the Stroop word in half of the trials. Nonmatched cue-word color pairs assessed selective attention, and face-word pairs assessed emotion. Relative to controls, DTI-based fiber tracking revealed lower inferior longitudinal fasciculus (ilf) integrity in HIV and ALC+HIV and lower uncinate fasciculus (uf) integrity in all three patient groups. Controls exhibited Stroop effects to positive face-word emotion, and greater interference was related to greater callosal, cingulum and ilf integrity. By contrast, HIV showed greater interference from negative Stroop words during color-nonmatch trials, correlating with greater uf compromise. For face trials, ALC and ALC+HIV showed greater Stroop-word interference, correlating with lower cingulate and callosal integrity. Thus, in HIV, conflict resolution was diminished when challenging conditions usurped resources needed to manage interference from negative emotion and to disengage attention from wrongly cued colors (nonmatch). In ALC and ALC+HIV, poorer callosal integrity was related to enhanced emotional interference suggesting curtailed interhemispheric exchange needed between preferentially right-hemispheric emotion and left-hemispheric Stroop-word functions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Integration of shallow gradients of Shh and Netrin-1 guides commissural axons.

PubMed

Sloan, Tyler F W; Qasaimeh, Mohammad A; Juncker, David; Yam, Patricia T; Charron, Frédéric

2015-03-01

During nervous system development, gradients of Sonic Hedgehog (Shh) and Netrin-1 attract growth cones of commissural axons toward the floor plate of the embryonic spinal cord. Mice defective for either Shh or Netrin-1 signaling have commissural axon guidance defects, suggesting that both Shh and Netrin-1 are required for correct axon guidance. However, how Shh and Netrin-1 collaborate to guide axons is not known. We first quantified the steepness of the Shh gradient in the spinal cord and found that it is mostly very shallow. We then developed an in vitro microfluidic guidance assay to simulate these shallow gradients. We found that axons of dissociated commissural neurons respond to steep but not shallow gradients of Shh or Netrin-1. However, when we presented axons with combined Shh and Netrin-1 gradients, they had heightened sensitivity to the guidance cues, turning in response to shallower gradients that were unable to guide axons when only one cue was present. Furthermore, these shallow gradients polarized growth cone Src-family kinase (SFK) activity only when Shh and Netrin-1 were combined, indicating that SFKs can integrate the two guidance cues. Together, our results indicate that Shh and Netrin-1 synergize to enable growth cones to sense shallow gradients in regions of the spinal cord where the steepness of a single guidance cue is insufficient to guide axons, and we identify a novel type of synergy that occurs when the steepness (and not the concentration) of a guidance cue is limiting.

Integration of Shallow Gradients of Shh and Netrin-1 Guides Commissural Axons

PubMed Central

Sloan, Tyler F. W.; Qasaimeh, Mohammad A.; Juncker, David; Yam, Patricia T.; Charron, Frédéric

2015-01-01

During nervous system development, gradients of Sonic Hedgehog (Shh) and Netrin-1 attract growth cones of commissural axons toward the floor plate of the embryonic spinal cord. Mice defective for either Shh or Netrin-1 signaling have commissural axon guidance defects, suggesting that both Shh and Netrin-1 are required for correct axon guidance. However, how Shh and Netrin-1 collaborate to guide axons is not known. We first quantified the steepness of the Shh gradient in the spinal cord and found that it is mostly very shallow. We then developed an in vitro microfluidic guidance assay to simulate these shallow gradients. We found that axons of dissociated commissural neurons respond to steep but not shallow gradients of Shh or Netrin-1. However, when we presented axons with combined Shh and Netrin-1 gradients, they had heightened sensitivity to the guidance cues, turning in response to shallower gradients that were unable to guide axons when only one cue was present. Furthermore, these shallow gradients polarized growth cone Src-family kinase (SFK) activity only when Shh and Netrin-1 were combined, indicating that SFKs can integrate the two guidance cues. Together, our results indicate that Shh and Netrin-1 synergize to enable growth cones to sense shallow gradients in regions of the spinal cord where the steepness of a single guidance cue is insufficient to guide axons, and we identify a novel type of synergy that occurs when the steepness (and not the concentration) of a guidance cue is limiting. PMID:25826604

The origin and dynamic evolution of chemical information transfer

PubMed Central

Steiger, Sandra; Schmitt, Thomas; Schaefer, H. Martin

2011-01-01

Although chemical communication is the most widespread form of communication, its evolution and diversity are not well understood. By integrating studies of a wide range of terrestrial plants and animals, we show that many chemicals are emitted, which can unintentionally provide information (cues) and, therefore, act as direct precursors for the evolution of intentional communication (signals). Depending on the content, design and the original function of the cue, there are predictable ways that selection can enhance the communicative function of chemicals. We review recent progress on how efficacy-based selection by receivers leads to distinct evolutionary trajectories of chemical communication. Because the original function of a cue may channel but also constrain the evolution of functional communication, we show that a broad perspective on multiple selective pressures acting upon chemicals provides important insights into the origin and dynamic evolution of chemical information transfer. Finally, we argue that integrating chemical ecology into communication theory may significantly enhance our understanding of the evolution, the design and the content of signals in general. PMID:21177681

White matter integrity of central executive network correlates with enhanced brain reactivity to smoking cues.

PubMed

Bi, Yanzhi; Yuan, Kai; Yu, Dahua; Wang, Ruonan; Li, Min; Li, Yangding; Zhai, Jinquan; Lin, Wei; Tian, Jie

2017-12-01

The attentional bias to smoking cues contributes to smoking cue reactivity and cognitive declines underlines smoking behaviors, which were probably associated with the central executive network (CEN). However, little is known about the implication of the structural connectivity of the CEN in smoking cue reactivity and cognitive control impairments in smokers. In the present study, the white matter structural connectivity of the CEN was quantified in 35 smokers and 26 non-smokers using the diffusion tensor imaging and deterministic fiber tractography methods. Smoking cue reactivity was evaluated using cue exposure tasks, and cognitive control performance was assessed by the Stroop task. Relative to non-smokers, smokers showed increased fractional anisotropy (FA) values of the bilateral CEN fiber tracts. The FA values of left CEN positively correlated with the smoking cue-induced activation of the dorsolateral prefrontal cortex and right middle occipital cortex in smokers. Meanwhile, the FA values of left CEN positively correlated with the incongruent errors during Stroop task in smokers. Collectively, the present study highlighted the role of the structural connectivity of the CEN in smoking cue reactivity and cognitive control performance, which may underpin the attentional bias to smoking cues and cognitive deficits in smokers. The multimodal imaging method by forging links from brain structure to brain function extended the notion that structural connections can modulate the brain activity in specific projection target regions. Hum Brain Mapp 38:6239-6249, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Zebrafish take their cue from temperature but not photoperiod for the seasonal plasticity of thermal performance.

PubMed

Condon, Catriona H; Chenoweth, Stephen F; Wilson, Robbie S

2010-11-01

Organisms adjust to seasonal variability in the environment by responding to cues that indicate environmental change. As most studies of seasonal phenotypic plasticity test only the effect of a single environmental cue, how animals may integrate information from multiple cues to fine-tune plastic responses remains largely unknown. We examined the interaction between correlated (seasonally matching) and conflicting (seasonally opposite) temperature and photoperiod cues on the acclimation of performance traits in male zebrafish, Danio rerio. We acclimated fish for 8 weeks and then tested the change in thermal dependence of maximum burst swimming and feeding rate between 8 and 38°C. We predicted that correlated environmental cues should induce a greater acclimation response than uncorrelated cues. However, we found that only temperature was important for the seasonal acclimation of performance traits in zebrafish. Thermal acclimation shifted the thermal performance curve of both traits. For maximum burst swimming, performance increased for each group near the acclimation temperature and reduced in environments that were far from their acclimation temperature. The feeding rate of cold-acclimated zebrafish was reduced across the test temperature range compared with that of warm-acclimated fish. Our study is the first that has found no effect of the covariation between temperature and photoperiod acclimation cues on locomotor performance in fishes. Our results support the intuitive idea that photoperiod may be a less important seasonal cue for animals living at lower latitudes.

Integration of reward signalling and appetite regulating peptide systems in the control of food-cue responses.

PubMed

Reichelt, A C; Westbrook, R F; Morris, M J

2015-11-01

Understanding the neurobiological substrates that encode learning about food-associated cues and how those signals are modulated is of great clinical importance especially in light of the worldwide obesity problem. Inappropriate or maladaptive responses to food-associated cues can promote over-consumption, leading to excessive energy intake and weight gain. Chronic exposure to foods rich in fat and sugar alters the reinforcing value of foods and weakens inhibitory neural control, triggering learned, but maladaptive, associations between environmental cues and food rewards. Thus, responses to food-associated cues can promote cravings and food-seeking by activating mesocorticolimbic dopamine neurocircuitry, and exert physiological effects including salivation. These responses may be analogous to the cravings experienced by abstaining drug addicts that can trigger relapse into drug self-administration. Preventing cue-triggered eating may therefore reduce the over-consumption seen in obesity and binge-eating disorder. In this review we discuss recent research examining how cues associated with palatable foods can promote reward-based feeding behaviours and the potential involvement of appetite-regulating peptides including leptin, ghrelin, orexin and melanin concentrating hormone. These peptide signals interface with mesolimbic dopaminergic regions including the ventral tegmental area to modulate reactivity to cues associated with palatable foods. Thus, a novel target for anti-obesity therapeutics is to reduce non-homeostatic, reward driven eating behaviour, which can be triggered by environmental cues associated with highly palatable, fat and sugar rich foods. © 2015 The British Pharmacological Society.

Differential processing of binocular and monocular gloss cues in human visual cortex.

PubMed

Sun, Hua-Chun; Di Luca, Massimiliano; Ban, Hiroshi; Muryy, Alexander; Fleming, Roland W; Welchman, Andrew E

2016-06-01

The visual impression of an object's surface reflectance ("gloss") relies on a range of visual cues, both monocular and binocular. Whereas previous imaging work has identified processing within ventral visual areas as important for monocular cues, little is known about cortical areas involved in processing binocular cues. Here, we used human functional MRI (fMRI) to test for brain areas selectively involved in the processing of binocular cues. We manipulated stereoscopic information to create four conditions that differed in their disparity structure and in the impression of surface gloss that they evoked. We performed multivoxel pattern analysis to find areas whose fMRI responses allow classes of stimuli to be distinguished based on their depth structure vs. material appearance. We show that higher dorsal areas play a role in processing binocular gloss information, in addition to known ventral areas involved in material processing, with ventral area lateral occipital responding to both object shape and surface material properties. Moreover, we tested for similarities between the representation of gloss from binocular cues and monocular cues. Specifically, we tested for transfer in the decoding performance of an algorithm trained on glossy vs. matte objects defined by either binocular or by monocular cues. We found transfer effects from monocular to binocular cues in dorsal visual area V3B/kinetic occipital (KO), suggesting a shared representation of the two cues in this area. These results indicate the involvement of mid- to high-level visual circuitry in the estimation of surface material properties, with V3B/KO potentially playing a role in integrating monocular and binocular cues. Copyright © 2016 the American Physiological Society.

Food and conspecific chemical cues modify visual behavior of zebrafish, Danio rerio.

PubMed

Stephenson, Jessica F; Partridge, Julian C; Whitlock, Kathleen E

2012-06-01

Animals use the different qualities of olfactory and visual sensory information to make decisions. Ethological and electrophysiological evidence suggests that there is cross-modal priming between these sensory systems in fish. We present the first experimental study showing that ecologically relevant chemical mixtures alter visual behavior, using adult male and female zebrafish, Danio rerio. Neutral-density filters were used to attenuate the light reaching the tank to an initial light intensity of 2.3×10(16) photons/s/m2. Fish were exposed to food cue and to alarm cue. The light intensity was then increased by the removal of one layer of filter (nominal absorbance 0.3) every minute until, after 10 minutes, the light level was 15.5×10(16) photons/s/m2. Adult male and female zebrafish responded to a moving visual stimulus at lower light levels if they had been first exposed to food cue, or to conspecific alarm cue. These results suggest the need for more integrative studies of sensory biology.

Estimating 3D tilt from local image cues in natural scenes

PubMed Central

Burge, Johannes; McCann, Brian C.; Geisler, Wilson S.

2016-01-01

Estimating three-dimensional (3D) surface orientation (slant and tilt) is an important first step toward estimating 3D shape. Here, we examine how three local image cues from the same location (disparity gradient, luminance gradient, and dominant texture orientation) should be combined to estimate 3D tilt in natural scenes. We collected a database of natural stereoscopic images with precisely co-registered range images that provide the ground-truth distance at each pixel location. We then analyzed the relationship between ground-truth tilt and image cue values. Our analysis is free of assumptions about the joint probability distributions and yields the Bayes optimal estimates of tilt, given the cue values. Rich results emerge: (a) typical tilt estimates are only moderately accurate and strongly influenced by the cardinal bias in the prior probability distribution; (b) when cue values are similar, or when slant is greater than 40°, estimates are substantially more accurate; (c) when luminance and texture cues agree, they often veto the disparity cue, and when they disagree, they have little effect; and (d) simplifying assumptions common in the cue combination literature is often justified for estimating tilt in natural scenes. The fact that tilt estimates are typically not very accurate is consistent with subjective impressions from viewing small patches of natural scene. The fact that estimates are substantially more accurate for a subset of image locations is also consistent with subjective impressions and with the hypothesis that perceived surface orientation, at more global scales, is achieved by interpolation or extrapolation from estimates at key locations. PMID:27738702

How much to trust the senses: Likelihood learning

PubMed Central

Sato, Yoshiyuki; Kording, Konrad P.

2014-01-01

Our brain often needs to estimate unknown variables from imperfect information. Our knowledge about the statistical distributions of quantities in our environment (called priors) and currently available information from sensory inputs (called likelihood) are the basis of all Bayesian models of perception and action. While we know that priors are learned, most studies of prior-likelihood integration simply assume that subjects know about the likelihood. However, as the quality of sensory inputs change over time, we also need to learn about new likelihoods. Here, we show that human subjects readily learn the distribution of visual cues (likelihood function) in a way that can be predicted by models of statistically optimal learning. Using a likelihood that depended on color context, we found that a learned likelihood generalized to new priors. Thus, we conclude that subjects learn about likelihood. PMID:25398975

Sequencing the Cortical Processing of Pitch-Evoking Stimuli using EEG Analysis and Source Estimation

PubMed Central

Butler, Blake E.; Trainor, Laurel J.

2012-01-01

Cues to pitch include spectral cues that arise from tonotopic organization and temporal cues that arise from firing patterns of auditory neurons. fMRI studies suggest a common pitch center is located just beyond primary auditory cortex along the lateral aspect of Heschl’s gyrus, but little work has examined the stages of processing for the integration of pitch cues. Using electroencephalography, we recorded cortical responses to high-pass filtered iterated rippled noise (IRN) and high-pass filtered complex harmonic stimuli, which differ in temporal and spectral content. The two stimulus types were matched for pitch saliency, and a mismatch negativity (MMN) response was elicited by infrequent pitch changes. The P1 and N1 components of event-related potentials (ERPs) are thought to arise from primary and secondary auditory areas, respectively, and to result from simple feature extraction. MMN is generated in secondary auditory cortex and is thought to act on feature-integrated auditory objects. We found that peak latencies of both P1 and N1 occur later in response to IRN stimuli than to complex harmonic stimuli, but found no latency differences between stimulus types for MMN. The location of each ERP component was estimated based on iterative fitting of regional sources in the auditory cortices. The sources of both the P1 and N1 components elicited by IRN stimuli were located dorsal to those elicited by complex harmonic stimuli, whereas no differences were observed for MMN sources across stimuli. Furthermore, the MMN component was located between the P1 and N1 components, consistent with fMRI studies indicating a common pitch region in lateral Heschl’s gyrus. These results suggest that while the spectral and temporal processing of different pitch-evoking stimuli involves different cortical areas during early processing, by the time the object-related MMN response is formed, these cues have been integrated into a common representation of pitch. PMID:22740836

Memory reactivation during rapid eye movement sleep promotes its generalization and integration in cortical stores.

PubMed

Sterpenich, Virginie; Schmidt, Christina; Albouy, Geneviève; Matarazzo, Luca; Vanhaudenhuyse, Audrey; Boveroux, Pierre; Degueldre, Christian; Leclercq, Yves; Balteau, Evelyne; Collette, Fabienne; Luxen, André; Phillips, Christophe; Maquet, Pierre

2014-06-01

Memory reactivation appears to be a fundamental process in memory consolidation. In this study we tested the influence of memory reactivation during rapid eye movement (REM) sleep on memory performance and brain responses at retrieval in healthy human participants. Fifty-six healthy subjects (28 women and 28 men, age [mean ± standard deviation]: 21.6 ± 2.2 y) participated in this functional magnetic resonance imaging (fMRI) study. Auditory cues were associated with pictures of faces during their encoding. These memory cues delivered during REM sleep enhanced subsequent accurate recollections but also false recognitions. These results suggest that reactivated memories interacted with semantically related representations, and induced new creative associations, which subsequently reduced the distinction between new and previously encoded exemplars. Cues had no effect if presented during stage 2 sleep, or if they were not associated with faces during encoding. Functional magnetic resonance imaging revealed that following exposure to conditioned cues during REM sleep, responses to faces during retrieval were enhanced both in a visual area and in a cortical region of multisensory (auditory-visual) convergence. These results show that reactivating memories during REM sleep enhances cortical responses during retrieval, suggesting the integration of recent memories within cortical circuits, favoring the generalization and schematization of the information.

Category-Specific Neural Oscillations Predict Recall Organization During Memory Search

PubMed Central

Morton, Neal W.; Kahana, Michael J.; Rosenberg, Emily A.; Baltuch, Gordon H.; Litt, Brian; Sharan, Ashwini D.; Sperling, Michael R.; Polyn, Sean M.

2013-01-01

Retrieved-context models of human memory propose that as material is studied, retrieval cues are constructed that allow one to target particular aspects of past experience. We examined the neural predictions of these models by using electrocorticographic/depth recordings and scalp electroencephalography (EEG) to characterize category-specific oscillatory activity, while participants studied and recalled items from distinct, neurally discriminable categories. During study, these category-specific patterns predict whether a studied item will be recalled. In the scalp EEG experiment, category-specific activity during study also predicts whether a given item will be recalled adjacent to other same-category items, consistent with the proposal that a category-specific retrieval cue is used to guide memory search. Retrieved-context models suggest that integrative neural circuitry is involved in the construction and maintenance of the retrieval cue. Consistent with this hypothesis, we observe category-specific patterns that rise in strength as multiple same-category items are studied sequentially, and find that individual differences in this category-specific neural integration during study predict the degree to which a participant will use category information to organize memory search. Finally, we track the deployment of this retrieval cue during memory search: Category-specific patterns are stronger when participants organize their responses according to the category of the studied material. PMID:22875859

Logical metonymy resolution in a words-as-cues framework: evidence from self-paced reading and probe recognition.

PubMed

Zarcone, Alessandra; Padó, Sebastian; Lenci, Alessandro

2014-06-01

Logical metonymy resolution (begin a book → begin reading a book or begin writing a book) has traditionally been explained either through complex lexical entries (qualia structures) or through the integration of the implicit event via post-lexical access to world knowledge. We propose that recent work within the words-as-cues paradigm can provide a more dynamic model of logical metonymy, accounting for early and dynamic integration of complex event information depending on previous contextual cues (agent and patient). We first present a self-paced reading experiment on German subordinate sentences, where metonymic sentences and their paraphrased version differ only in the presence or absence of the clause-final target verb (Der Konditor begann die Glasur → Der Konditor begann, die Glasur aufzutragen/The baker began the icing → The baker began spreading the icing). Longer reading times at the target verb position in a high-typicality condition (baker + icing → spread ) compared to a low-typicality (but still plausible) condition (child + icing → spread) suggest that we make use of knowledge activated by lexical cues to build expectations about events. The early and dynamic integration of event knowledge in metonymy interpretation is bolstered by further evidence from a second experiment using the probe recognition paradigm. Presenting covert events as probes following a high-typicality or a low-typicality metonymic sentence (Der Konditor begann die Glasur → AUFTRAGEN/The baker began the icing → SPREAD), we obtain an analogous effect of typicality at 100 ms interstimulus interval. © 2014 Cognitive Science Society, Inc.

Virtual reality applications in improving postural control and minimizing falls.

PubMed

Virk, Sumandeep; McConville, Kristiina M Valter

2006-01-01

Maintaining balance under all conditions is an absolute requirement for humans. Orientation in space and balance maintenance requires inputs from the vestibular, the visual, the proprioceptive and the somatosensory systems. All the cues coming from these systems are integrated by the central nervous system (CNS) to employ different strategies for orientation and balance. How the CNS integrates all the inputs and makes cognitive decisions about balance strategies has been an area of interest for biomedical engineers for a long time. More interesting is the fact that in the absence of one or more cues, or when the input from one of the sensors is skewed, the CNS "adapts" to the new environment and gives less weight to the conflicting inputs [1]. The focus of this paper is a review of different strategies and models put forward by researchers to explain the integration of these sensory cues. Also, the paper compares the different approaches used by young and old adults in maintaining balance. Since with age the musculoskeletal, visual and vestibular system deteriorates, the older subjects have to compensate for these impaired sensory cues for postural stability. The paper also discusses the applications of virtual reality in rehabilitation programs not only for balance in the elderly but also in occupational falls. Virtual reality has profound applications in the field of balance rehabilitation and training because of its relatively low cost. Studies will be conducted to evaluate the effectiveness of virtual reality training in modifying the head and eye movement strategies, and determine the role of these responses in the maintenance of balance.

Modeling human perception and estimation of kinematic responses during aircraft landing

NASA Technical Reports Server (NTRS)

Schmidt, David K.; Silk, Anthony B.

1988-01-01

The thrust of this research is to determine estimation accuracy of aircraft responses based on observed cues. By developing the geometric relationships between the outside visual scene and the kinematics during landing, visual and kinesthetic cues available to the pilot were modeled. Both fovial and peripheral vision was examined. The objective was to first determine estimation accuracy in a variety of flight conditions, and second to ascertain which parameters are most important and lead to the best achievable accuracy in estimating the actual vehicle response. It was found that altitude estimation was very sensitive to the FOV. For this model the motion cue of perceived vertical acceleration was shown to be less important than the visual cues. The inclusion of runway geometry in the visual scene increased estimation accuracy in most cases. Finally, it was shown that for this model if the pilot has an incorrect internal model of the system kinematics the choice of observations thought to be 'optimal' may in fact be suboptimal.

Extinction of cue-evoked drug-seeking relies on degrading hierarchical instrumental expectancies

PubMed Central

Hogarth, Lee; Retzler, Chris; Munafò, Marcus R.; Tran, Dominic M.D.; Troisi, Joseph R.; Rose, Abigail K.; Jones, Andrew; Field, Matt

2014-01-01

There has long been need for a behavioural intervention that attenuates cue-evoked drug-seeking, but the optimal method remains obscure. To address this, we report three approaches to extinguish cue-evoked drug-seeking measured in a Pavlovian to instrumental transfer design, in non-treatment seeking adult smokers and alcohol drinkers. The results showed that the ability of a drug stimulus to transfer control over a separately trained drug-seeking response was not affected by the stimulus undergoing Pavlovian extinction training in experiment 1, but was abolished by the stimulus undergoing discriminative extinction training in experiment 2, and was abolished by explicit verbal instructions stating that the stimulus did not signal a more effective response-drug contingency in experiment 3. These data suggest that cue-evoked drug-seeking is mediated by a propositional hierarchical instrumental expectancy that the drug-seeking response is more likely to be rewarded in that stimulus. Methods which degraded this hierarchical expectancy were effective in the laboratory, and so may have therapeutic potential. PMID:25011113

Automatic Mechanisms for Social Attention Are Culturally Penetrable.

PubMed

Cohen, Adam S; Sasaki, Joni Y; German, Tamsin C; Kim, Heejung S

2017-01-01

Are mechanisms for social attention influenced by culture? Evidence that social attention is triggered automatically by bottom-up gaze cues and is uninfluenced by top-down verbal instructions may suggest it operates in the same way everywhere. Yet considerations from evolutionary and cultural psychology suggest that specific aspects of one's cultural background may have consequence for the way mechanisms for social attention develop and operate. In more interdependent cultures, the scope of social attention may be broader, focusing on more individuals and relations between those individuals. We administered a multi-gaze cueing task requiring participants to fixate a foreground face flanked by background faces and measured shifts in attention using eye tracking. For European Americans, gaze cueing did not depend on the direction of background gaze cues, suggesting foreground gaze alone drives automatic attention shifting; for East Asians, cueing patterns differed depending on whether the foreground cue matched or mismatched background cues, suggesting foreground and background gaze information were integrated. These results demonstrate that cultural background influences the social attention system by shifting it into a narrow or broad mode of operation and, importantly, provides evidence challenging the assumption that mechanisms underlying automatic social attention are necessarily rigid and impenetrable to culture. Copyright © 2015 Cognitive Science Society, Inc.

The polarization compass dominates over idiothetic cues in path integration of desert ants.

PubMed

Lebhardt, Fleur; Koch, Julja; Ronacher, Bernhard

2012-02-01

Desert ants, Cataglyphis, use the sky's pattern of polarized light as a compass reference for navigation. However, they do not fully exploit the complexity of this pattern, rather - as proposed previously - they assess their walking direction by means of an approximate solution based on a simplified internal template. Approximate rules are error-prone. We therefore asked whether the ants use additional cues to improve the accuracy of directional decisions, and focused on 'idiothetic' cues, i.e. cues based on information from proprioceptors. We trained ants in a channel system that was covered with a polarization filter, providing only a single e-vector direction as a directional 'celestial' cue. Then we observed their homebound runs on a test field, allowing full view of the sky. In crucial experiments, the ants were exposed to a cue conflict, in which sky compass and idiothetic information disagreed, by training them in a straight channel that provided a change in e-vector direction. The results indicated that the polarization information completely dominates over idiothetic cues. Two path segments with different e-vector orientations are combined linearly to a summed home vector. Our data provide additional evidence that Cataglyphis uses a simplified internal template to derive directional information from the sky's polarization pattern.

Role of hippocampus in polymodal-cue guided tasks in rats.

PubMed

Miniaci, Maria Concetta; Lippiello, Pellegrino; Monda, Marcellino; Scotto, Pietro

2016-09-01

To examine how signals from different sensory modalities are integrated to generate an appropriate goal-oriented behavior, we trained rats in an eight-arm radial maze to visit a cue arm provided with intramaze cues from different sensory modalities, i.e. visual, tactile and auditory, in order to obtain a reward. When the same rats were then examined on test trials in which the cue arm contained one of the stimuli that the animals were trained with (i.e. light, sound or rough sheet), they showed a significant impairment with respect to the performance on the polymodal-cue task. The contribution of the dorsal hippocampus to the acquisition and retention of polymodal-cue guided task was also examined. We found that rats with dorsal hippocampal lesions before training showed a significant deficit in the acquisition of polymodal-cue oriented task that improved with overtraining. The selective lesion of the dorsal hippocampus after training disrupted memory retention, but the animals' performance improved following retraining of the polymodal task. All hippocampal lesioned rats displayed an impaired performance on the unimodal test. These findings suggest that the dorsal hippocampus contributes to the processing of multimodal sensory information for the associative memory formation and consolidation. Copyright © 2016 Elsevier B.V. All rights reserved.

Binaural noise reduction via cue-preserving MMSE filter and adaptive-blocking-based noise PSD estimation

NASA Astrophysics Data System (ADS)

Azarpour, Masoumeh; Enzner, Gerald

2017-12-01

Binaural noise reduction, with applications for instance in hearing aids, has been a very significant challenge. This task relates to the optimal utilization of the available microphone signals for the estimation of the ambient noise characteristics and for the optimal filtering algorithm to separate the desired speech from the noise. The additional requirements of low computational complexity and low latency further complicate the design. A particular challenge results from the desired reconstruction of binaural speech input with spatial cue preservation. The latter essentially diminishes the utility of multiple-input/single-output filter-and-sum techniques such as beamforming. In this paper, we propose a comprehensive and effective signal processing configuration with which most of the aforementioned criteria can be met suitably. This relates especially to the requirement of efficient online adaptive processing for noise estimation and optimal filtering while preserving the binaural cues. Regarding noise estimation, we consider three different architectures: interaural (ITF), cross-relation (CR), and principal-component (PCA) target blocking. An objective comparison with two other noise PSD estimation algorithms demonstrates the superiority of the blocking-based noise estimators, especially the CR-based and ITF-based blocking architectures. Moreover, we present a new noise reduction filter based on minimum mean-square error (MMSE), which belongs to the class of common gain filters, hence being rigorous in terms of spatial cue preservation but also efficient and competitive for the acoustic noise reduction task. A formal real-time subjective listening test procedure is also developed in this paper. The proposed listening test enables a real-time assessment of the proposed computationally efficient noise reduction algorithms in a realistic acoustic environment, e.g., considering time-varying room impulse responses and the Lombard effect. The listening test outcome reveals that the signals processed by the blocking-based algorithms are significantly preferred over the noisy signal in terms of instantaneous noise attenuation. Furthermore, the listening test data analysis confirms the conclusions drawn based on the objective evaluation.

Developmental prosopagnosia and super-recognition: no special role for surface reflectance processing.

PubMed

Russell, Richard; Chatterjee, Garga; Nakayama, Ken

2012-01-01

Face recognition by normal subjects depends in roughly equal proportions on shape and surface reflectance cues, while object recognition depends predominantly on shape cues. It is possible that developmental prosopagnosics are deficient not in their ability to recognize faces per se, but rather in their ability to use reflectance cues. Similarly, super-recognizers' exceptional ability with face recognition may be a result of superior surface reflectance perception and memory. We tested this possibility by administering tests of face perception and face recognition in which only shape or reflectance cues are available to developmental prosopagnosics, super-recognizers, and control subjects. Face recognition ability and the relative use of shape and pigmentation were unrelated in all the tests. Subjects who were better at using shape or reflectance cues were also better at using the other type of cue. These results do not support the proposal that variation in surface reflectance perception ability is the underlying cause of variation in face recognition ability. Instead, these findings support the idea that face recognition ability is related to neural circuits using representations that integrate shape and pigmentation information. Copyright © 2011 Elsevier Ltd. All rights reserved.

Visual form predictions facilitate auditory processing at the N1.

PubMed

Paris, Tim; Kim, Jeesun; Davis, Chris

2017-02-20

Auditory-visual (AV) events often involve a leading visual cue (e.g. auditory-visual speech) that allows the perceiver to generate predictions about the upcoming auditory event. Electrophysiological evidence suggests that when an auditory event is predicted, processing is sped up, i.e., the N1 component of the ERP occurs earlier (N1 facilitation). However, it is not clear (1) whether N1 facilitation is based specifically on predictive rather than multisensory integration and (2) which particular properties of the visual cue it is based on. The current experiment used artificial AV stimuli in which visual cues predicted but did not co-occur with auditory cues. Visual form cues (high and low salience) and the auditory-visual pairing were manipulated so that auditory predictions could be based on form and timing or on timing only. The results showed that N1 facilitation occurred only for combined form and temporal predictions. These results suggest that faster auditory processing (as indicated by N1 facilitation) is based on predictive processing generated by a visual cue that clearly predicts both what and when the auditory stimulus will occur. Copyright © 2016. Published by Elsevier Ltd.

Prediction and constraint in audiovisual speech perception

PubMed Central

Peelle, Jonathan E.; Sommers, Mitchell S.

2015-01-01

During face-to-face conversational speech listeners must efficiently process a rapid and complex stream of multisensory information. Visual speech can serve as a critical complement to auditory information because it provides cues to both the timing of the incoming acoustic signal (the amplitude envelope, influencing attention and perceptual sensitivity) and its content (place and manner of articulation, constraining lexical selection). Here we review behavioral and neurophysiological evidence regarding listeners' use of visual speech information. Multisensory integration of audiovisual speech cues improves recognition accuracy, particularly for speech in noise. Even when speech is intelligible based solely on auditory information, adding visual information may reduce the cognitive demands placed on listeners through increasing precision of prediction. Electrophysiological studies demonstrate oscillatory cortical entrainment to speech in auditory cortex is enhanced when visual speech is present, increasing sensitivity to important acoustic cues. Neuroimaging studies also suggest increased activity in auditory cortex when congruent visual information is available, but additionally emphasize the involvement of heteromodal regions of posterior superior temporal sulcus as playing a role in integrative processing. We interpret these findings in a framework of temporally-focused lexical competition in which visual speech information affects auditory processing to increase sensitivity to auditory information through an early integration mechanism, and a late integration stage that incorporates specific information about a speaker's articulators to constrain the number of possible candidates in a spoken utterance. Ultimately it is words compatible with both auditory and visual information that most strongly determine successful speech perception during everyday listening. Thus, audiovisual speech perception is accomplished through multiple stages of integration, supported by distinct neuroanatomical mechanisms. PMID:25890390

Combinatorial screening of 3D biomaterial properties that promote myofibrogenesis for mesenchymal stromal cell-based heart valve tissue engineering.

PubMed

Usprech, Jenna; Romero, David A; Amon, Cristina H; Simmons, Craig A

2017-08-01

The physical and chemical properties of a biomaterial integrate with soluble cues in the cell microenvironment to direct cell fate and function. Predictable biomaterial-based control of integrated cell responses has been investigated with two-dimensional (2D) screening platforms, but integrated responses in 3D have largely not been explored systematically. To address this need, we developed a screening platform using polyethylene glycol norbornene (PEG-NB) as a model biomaterial with which the polymer wt% (to control elastic modulus) and adhesion peptide types (RGD, DGEA, YIGSR) and densities could be controlled independently and combinatorially in arrays of 3D hydrogels. We applied this platform and regression modeling to identify combinations of biomaterial and soluble biochemical (TGF-β1) factors that best promoted myofibrogenesis of human mesenchymal stromal cells (hMSCs) in order to inform our understanding of regenerative processes for heart valve tissue engineering. In contrast to 2D culture, our screens revealed that soft hydrogels (low PEG-NB wt%) best promoted spread myofibroblastic cells that expressed high levels of α-smooth muscle actin (α-SMA) and collagen type I. High concentrations of RGD enhanced α-SMA expression in the presence of TGF-β1 and cell spreading regardless of whether TGF-β1 was in the culture medium. Strikingly, combinations of peptides that maximized collagen expression depended on the presence or absence of TGF-β1, indicating that biomaterial properties can modulate MSC response to soluble signals. This combination of a 3D biomaterial array screening platform with statistical modeling is broadly applicable to systematically identify combinations of biomaterial and microenvironmental conditions that optimally guide cell responses. We present a novel screening platform and methodology to model and identify how combinations of biomaterial and microenvironmental conditions guide cell phenotypes in 3D. Our approach to systematically identify complex relationships between microenvironmental cues and cell responses enables greater predictive power over cell fate in conditions with interacting material design factors. We demonstrate that this approach not only predicts that mesenchymal stromal cell (MSC) myofibrogenesis is promoted by soft, porous 3D biomaterials, but also generated new insights which demonstrate how biomaterial properties can differentially modulate MSC response to soluble signals. An additional benefit of the process includes utilizing both parametric and non parametric analyses which can demonstrate dominant significant trends as well as subtle interactions between biochemical and biomaterial cues. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

What information is necessary for speech categorization? Harnessing variability in the speech signal by integrating cues computed relative to expectations

PubMed Central

McMurray, Bob; Jongman, Allard

2012-01-01

Most theories of categorization emphasize how continuous perceptual information is mapped to categories. However, equally important is the informational assumptions of a model, the type of information subserving this mapping. This is crucial in speech perception where the signal is variable and context-dependent. This study assessed the informational assumptions of several models of speech categorization, in particular, the number of cues that are the basis of categorization and whether these cues represent the input veridically or have undergone compensation. We collected a corpus of 2880 fricative productions (Jongman, Wayland & Wong, 2000) spanning many talker- and vowel-contexts and measured 24 cues for each. A subset was also presented to listeners in an 8AFC phoneme categorization task. We then trained a common classification model based on logistic regression to categorize the fricative from the cue values, and manipulated the information in the training set to contrast 1) models based on a small number of invariant cues; 2) models using all cues without compensation, and 3) models in which cues underwent compensation for contextual factors. Compensation was modeled by Computing Cues Relative to Expectations (C-CuRE), a new approach to compensation that preserves fine-grained detail in the signal. Only the compensation model achieved a similar accuracy to listeners, and showed the same effects of context. Thus, even simple categorization metrics can overcome the variability in speech when sufficient information is available and compensation schemes like C-CuRE are employed. PMID:21417542

A designated odor-language integration system in the human brain.

PubMed

Olofsson, Jonas K; Hurley, Robert S; Bowman, Nicholas E; Bao, Xiaojun; Mesulam, M-Marsel; Gottfried, Jay A

2014-11-05

Odors are surprisingly difficult to name, but the mechanism underlying this phenomenon is poorly understood. In experiments using event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI), we investigated the physiological basis of odor naming with a paradigm where olfactory and visual object cues were followed by target words that either matched or mismatched the cue. We hypothesized that word processing would not only be affected by its semantic congruency with the preceding cue, but would also depend on the cue modality (olfactory or visual). Performance was slower and less precise when linking a word to its corresponding odor than to its picture. The ERP index of semantic incongruity (N400), reflected in the comparison of nonmatching versus matching target words, was more constrained to posterior electrode sites and lasted longer on odor-cue (vs picture-cue) trials. In parallel, fMRI cross-adaptation in the right orbitofrontal cortex (OFC) and the left anterior temporal lobe (ATL) was observed in response to words when preceded by matching olfactory cues, but not by matching visual cues. Time-series plots demonstrated increased fMRI activity in OFC and ATL at the onset of the odor cue itself, followed by response habituation after processing of a matching (vs nonmatching) target word, suggesting that predictive perceptual representations in these regions are already established before delivery and deliberation of the target word. Together, our findings underscore the modality-specific anatomy and physiology of object identification in the human brain. Copyright © 2014 the authors 0270-6474/14/3414864-10$15.00/0.

How do People Solve the “Weather Prediction” Task?: Individual Variability in Strategies for Probabilistic Category Learning

PubMed Central

Gluck, Mark A.; Shohamy, Daphna; Myers, Catherine

2002-01-01

Probabilistic category learning is often assumed to be an incrementally learned cognitive skill, dependent on nondeclarative memory systems. One paradigm in particular, the weather prediction task, has been used in over half a dozen neuropsychological and neuroimaging studies to date. Because of the growing interest in using this task and others like it as behavioral tools for studying the cognitive neuroscience of cognitive skill learning, it becomes especially important to understand how subjects solve this kind of task and whether all subjects learn it in the same way. We present here new experimental and theoretical analyses of the weather prediction task that indicate that there are at least three different strategies that describe how subjects learn this task. (1) An optimal multi-cue strategy, in which they respond to each pattern on the basis of associations of all four cues with each outcome; (2) a one-cue strategy, in which they respond on the basis of presence or absence of a single cue, disregarding all other cues; or (3) a singleton strategy, in which they learn only about the four patterns that have only one cue present and all others absent. This variability in how subjects approach this task may have important implications for interpreting how different brain regions are involved in probabilistic category learning. PMID:12464701

The Benefit of Attention-to-Memory Depends on the Interplay of Memory Capacity and Memory Load

PubMed Central

Lim, Sung-Joo; Wöstmann, Malte; Geweke, Frederik; Obleser, Jonas

2018-01-01

Humans can be cued to attend to an item in memory, which facilitates and enhances the perceptual precision in recalling this item. Here, we demonstrate that this facilitating effect of attention-to-memory hinges on the overall degree of memory load. The benefit an individual draws from attention-to-memory depends on her overall working memory performance, measured as sensitivity (d′) in a retroactive cue (retro-cue) pitch discrimination task. While listeners maintained 2, 4, or 6 auditory syllables in memory, we provided valid or neutral retro-cues to direct listeners’ attention to one, to-be-probed syllable in memory. Participants’ overall memory performance (i.e., perceptual sensitivity d′) was relatively unaffected by the presence of valid retro-cues across memory loads. However, a more fine-grained analysis using psychophysical modeling shows that valid retro-cues elicited faster pitch-change judgments and improved perceptual precision. Importantly, as memory load increased, listeners’ overall working memory performance correlated with inter-individual differences in the degree to which precision improved (r = 0.39, p = 0.029). Under high load, individuals with low working memory profited least from attention-to-memory. Our results demonstrate that retrospective attention enhances perceptual precision of attended items in memory but listeners’ optimal use of informative cues depends on their overall memory abilities. PMID:29520246

The shaping of social perception by stimulus and knowledge cues to human animacy

PubMed Central

Ramsey, Richard; Liepelt, Roman; Prinz, Wolfgang; Hamilton, Antonia F. de C.

2016-01-01

Although robots are becoming an ever-growing presence in society, we do not hold the same expectations for robots as we do for humans, nor do we treat them the same. As such, the ability to recognize cues to human animacy is fundamental for guiding social interactions. We review literature that demonstrates cortical networks associated with person perception, action observation and mentalizing are sensitive to human animacy information. In addition, we show that most prior research has explored stimulus properties of artificial agents (humanness of appearance or motion), with less investigation into knowledge cues (whether an agent is believed to have human or artificial origins). Therefore, currently little is known about the relationship between stimulus and knowledge cues to human animacy in terms of cognitive and brain mechanisms. Using fMRI, an elaborate belief manipulation, and human and robot avatars, we found that knowledge cues to human animacy modulate engagement of person perception and mentalizing networks, while stimulus cues to human animacy had less impact on social brain networks. These findings demonstrate that self–other similarities are not only grounded in physical features but are also shaped by prior knowledge. More broadly, as artificial agents fulfil increasingly social roles, a challenge for roboticists will be to manage the impact of pre-conceived beliefs while optimizing human-like design. PMID:26644594

The shaping of social perception by stimulus and knowledge cues to human animacy.

PubMed

Cross, Emily S; Ramsey, Richard; Liepelt, Roman; Prinz, Wolfgang; de C Hamilton, Antonia F

2016-01-19

Although robots are becoming an ever-growing presence in society, we do not hold the same expectations for robots as we do for humans, nor do we treat them the same. As such, the ability to recognize cues to human animacy is fundamental for guiding social interactions. We review literature that demonstrates cortical networks associated with person perception, action observation and mentalizing are sensitive to human animacy information. In addition, we show that most prior research has explored stimulus properties of artificial agents (humanness of appearance or motion), with less investigation into knowledge cues (whether an agent is believed to have human or artificial origins). Therefore, currently little is known about the relationship between stimulus and knowledge cues to human animacy in terms of cognitive and brain mechanisms. Using fMRI, an elaborate belief manipulation, and human and robot avatars, we found that knowledge cues to human animacy modulate engagement of person perception and mentalizing networks, while stimulus cues to human animacy had less impact on social brain networks. These findings demonstrate that self-other similarities are not only grounded in physical features but are also shaped by prior knowledge. More broadly, as artificial agents fulfil increasingly social roles, a challenge for roboticists will be to manage the impact of pre-conceived beliefs while optimizing human-like design. © 2015 The Authors.

Optimization of Apparatus Design and Behavioral Measures for the Assessment of Visuo-Spatial Learning and Memory of Mice on the Barnes Maze

ERIC Educational Resources Information Center

O'Leary, Timothy P.; Brown, Richard E.

2013-01-01

We have previously shown that apparatus design can affect visual-spatial cue use and memory performance of mice on the Barnes maze. The present experiment extends these findings by determining the optimal behavioral measures and test procedure for analyzing visuo-spatial learning and memory in three different Barnes maze designs. Male and female…

Processing of pictorial food stimuli in patients with eating disorders--a systematic review.

PubMed

Giel, Katrin Elisabeth; Teufel, Martin; Friederich, Hans-Christoph; Hautzinger, Martin; Enck, Paul; Zipfel, Stephan

2011-03-01

The processing of food cues in eating-disordered patients has recently been increasingly investigated. Outlined is current evidence from pictorial food stimuli studies. PubMed and PsychINFO were searched for quantitative pictorial food stimuli studies investigating healthy controls and expert-diagnosed eating-disordered patients. Patients with eating disorders (ED) demonstrated cue reactivity to food stimuli. Results from functional imaging suggest sensory disengagement and higher emotional involvement while self-reported data and facial EMG revealed that food pictures were perceived as less pleasurable. Different experimental paradigms have demonstrated an attentional bias for food cues in ED. Currently, psychophysiological data is widely inconclusive. Evidence suggests cue reactivity to food pictures in eating-disordered patients. However, the overall picture is inconclusive because methodological problems and the integration of findings from different experimental approaches pose a challenge to the research field. Copyright © 2009 Wiley Periodicals, Inc.

The phonological-distributional coherence hypothesis: cross-linguistic evidence in language acquisition.

PubMed

Monaghan, Padraic; Christiansen, Morten H; Chater, Nick

2007-12-01

Several phonological and prosodic properties of words have been shown to relate to differences between grammatical categories. Distributional information about grammatical categories is also a rich source in the child's language environment. In this paper we hypothesise that such cues operate in tandem for developing the child's knowledge about grammatical categories. We term this the Phonological-Distributional Coherence Hypothesis (PDCH). We tested the PDCH by analysing phonological and distributional information in distinguishing open from closed class words and nouns from verbs in four languages: English, Dutch, French, and Japanese. We found an interaction between phonological and distributional cues for all four languages indicating that when distributional cues were less reliable, phonological cues were stronger. This provides converging evidence that language is structured such that language learning benefits from the integration of information about category from contextual and sound-based sources, and that the child's language environment is less impoverished than we might suspect.

Development and Validation of Videotaped Scenarios

PubMed Central

Noel, Nora E.; Maisto, Stephen A.; Johnson, James D.; Jackson, Lee A.; Goings, Christopher D.; Hagman, Brett T.

2013-01-01

Researchers using scenarios often neglect to validate perceived content and salience of embedded stimuli specifically with intended participants, even when such meaning is integral to the study. For example, sex and aggression stimuli are heavily influenced by culture, so participants may not perceive what researchers intended in sexual aggression scenarios. Using four studies, the authors describe the method of scenario validation to produce two videos assessing alcohol-related sexual aggression. Both videos are identical except for the presence in one video of antiforce cues that are extremely salient to the young heterosexual men. Focus groups and questionnaires validate these men's perceptions that (a) the woman was sexually interested, (b) the sexual cues were salient, (c) the antiforce cues were salient (antiaggression video only), and (e) these antiforce cues inhibited acceptance of forced sex. Results show the value of carefully selecting and validating content when assessing socially volatile variables and provide a useful template for developing culturally valid scenarios. PMID:18252938

Desert ants learn vibration and magnetic landmarks.

PubMed

Buehlmann, Cornelia; Hansson, Bill S; Knaden, Markus

2012-01-01

The desert ants Cataglyphis navigate not only by path integration but also by using visual and olfactory landmarks to pinpoint the nest entrance. Here we show that Cataglyphis noda can additionally use magnetic and vibrational landmarks as nest-defining cues. The magnetic field may typically provide directional rather than positional information, and vibrational signals so far have been shown to be involved in social behavior. Thus it remains questionable if magnetic and vibration landmarks are usually provided by the ants' habitat as nest-defining cues. However, our results point to the flexibility of the ants' navigational system, which even makes use of cues that are probably most often sensed in a different context.

Effects of Emotional Intelligence on the Impression of Irony Created by the Mismatch between Verbal and Nonverbal Cues.

PubMed

Jacob, Heike; Kreifelts, Benjamin; Nizielski, Sophia; Schütz, Astrid; Wildgruber, Dirk

2016-01-01

Emotional information is conveyed through verbal and nonverbal signals, with nonverbal cues often being considered the decisive factor in the judgment of others' emotional states. The aim of the present study was to examine how verbal and nonverbal cues are integrated by perceivers. More specifically, we tested whether the mismatch between verbal and nonverbal information was perceived as an expression of irony. Moreover, we investigated the effects of emotional intelligence on the impression of irony. The findings revealed that the mismatch between verbal and nonverbal information created the impression of irony. Furthermore, participants higher in emotional intelligence were faster at rating such stimuli as ironic expressions.

Effects of Emotional Intelligence on the Impression of Irony Created by the Mismatch between Verbal and Nonverbal Cues

PubMed Central

Jacob, Heike; Kreifelts, Benjamin; Nizielski, Sophia; Schütz, Astrid; Wildgruber, Dirk

2016-01-01

Emotional information is conveyed through verbal and nonverbal signals, with nonverbal cues often being considered the decisive factor in the judgment of others’ emotional states. The aim of the present study was to examine how verbal and nonverbal cues are integrated by perceivers. More specifically, we tested whether the mismatch between verbal and nonverbal information was perceived as an expression of irony. Moreover, we investigated the effects of emotional intelligence on the impression of irony. The findings revealed that the mismatch between verbal and nonverbal information created the impression of irony. Furthermore, participants higher in emotional intelligence were faster at rating such stimuli as ironic expressions. PMID:27716831

Musically cued gait-training improves both perceptual and motor timing in Parkinson's disease.

PubMed

Benoit, Charles-Etienne; Dalla Bella, Simone; Farrugia, Nicolas; Obrig, Hellmuth; Mainka, Stefan; Kotz, Sonja A

2014-01-01

It is well established that auditory cueing improves gait in patients with idiopathic Parkinson's disease (IPD). Disease-related reductions in speed and step length can be improved by providing rhythmical auditory cues via a metronome or music. However, effects on cognitive aspects of motor control have yet to be thoroughly investigated. If synchronization of movement to an auditory cue relies on a supramodal timing system involved in perceptual, motor, and sensorimotor integration, auditory cueing can be expected to affect both motor and perceptual timing. Here, we tested this hypothesis by assessing perceptual and motor timing in 15 IPD patients before and after a 4-week music training program with rhythmic auditory cueing. Long-term effects were assessed 1 month after the end of the training. Perceptual and motor timing was evaluated with a battery for the assessment of auditory sensorimotor and timing abilities and compared to that of age-, gender-, and education-matched healthy controls. Prior to training, IPD patients exhibited impaired perceptual and motor timing. Training improved patients' performance in tasks requiring synchronization with isochronous sequences, and enhanced their ability to adapt to durational changes in a sequence in hand tapping tasks. Benefits of cueing extended to time perception (duration discrimination and detection of misaligned beats in musical excerpts). The current results demonstrate that auditory cueing leads to benefits beyond gait and support the idea that coupling gait to rhythmic auditory cues in IPD patients relies on a neuronal network engaged in both perceptual and motor timing.

Integration of reward signalling and appetite regulating peptide systems in the control of food‐cue responses

PubMed Central

Westbrook, R F; Morris, M J

2015-01-01

Understanding the neurobiological substrates that encode learning about food‐associated cues and how those signals are modulated is of great clinical importance especially in light of the worldwide obesity problem. Inappropriate or maladaptive responses to food‐associated cues can promote over‐consumption, leading to excessive energy intake and weight gain. Chronic exposure to foods rich in fat and sugar alters the reinforcing value of foods and weakens inhibitory neural control, triggering learned, but maladaptive, associations between environmental cues and food rewards. Thus, responses to food‐associated cues can promote cravings and food‐seeking by activating mesocorticolimbic dopamine neurocircuitry, and exert physiological effects including salivation. These responses may be analogous to the cravings experienced by abstaining drug addicts that can trigger relapse into drug self‐administration. Preventing cue‐triggered eating may therefore reduce the over‐consumption seen in obesity and binge‐eating disorder. In this review we discuss recent research examining how cues associated with palatable foods can promote reward‐based feeding behaviours and the potential involvement of appetite‐regulating peptides including leptin, ghrelin, orexin and melanin concentrating hormone. These peptide signals interface with mesolimbic dopaminergic regions including the ventral tegmental area to modulate reactivity to cues associated with palatable foods. Thus, a novel target for anti‐obesity therapeutics is to reduce non‐homeostatic, reward driven eating behaviour, which can be triggered by environmental cues associated with highly palatable, fat and sugar rich foods. PMID:26403657

Effects of a social cue on reproductive development and pre-alternate molt in seasonally breeding migrant and resident female songbirds (Zonotrichia leucophrys).

PubMed

Chmura, Helen E; Meddle, Simone L; Wingfield, John C; Hahn, Thomas P

2017-08-15

To time reproduction optimally, birds have evolved diverse mechanisms by which they respond to environmental changes that help them anticipate and prepare for the breeding season. While residents initiate reproductive preparation and breed in the same geographic location, migrant birds simultaneously prepare for breeding and migration far from their breeding grounds. As a result, it is hypothesized that migrant and resident birds use environmental cues differently to prepare to breed and that there is adaptive specialization in mechanisms regulating reproductive preparation. Specifically, residents are expected to rely more on non-photic cues (e.g. food, temperature, social cues) than migrants. We tested this general prediction using a social cue manipulation. First, we compared the effects of subspecies-appropriate recorded male song on reproductive development in migrants and residents on a naturally increasing photoperiod. Second, we tested the sensitivity of migrant-specific life history events (fattening and pre-alternate molt) to song treatment. After 82 days, residents had higher luteinizing hormone and greater ovarian development than migrants, but song treatment had no effect on these metrics in either subspecies. Song advanced pre-alternate molt but had no effect on fattening in migrants. While our study does not support specialization in social cue use in migrants and residents, it is consistent with findings in the literature of specialization in photoperiodic response. It also demonstrates for the first time that social cues can influence molt in a migrant species. Additional findings from a pilot study looking at responses to a live male suggest it is important to test other kinds of social cues. © 2017. Published by The Company of Biologists Ltd.

Using Dynamic Interface Modeling and Simulation to Develop a Launch and Recovery Flight Simulation for a UH-60A Blackhawk

NASA Technical Reports Server (NTRS)

Sweeney, Christopher; Bunnell, John; Chung, William; Giovannetti, Dean; Mikula, Julie; Nicholson, Bob; Roscoe, Mike

2001-01-01

Joint Shipboard Helicopter Integration Process (JSHIP) is a Joint Test and Evaluation (JT&E) program sponsored by the Office of the Secretary of Defense (OSD). Under the JSHDP program is a simulation effort referred to as the Dynamic Interface Modeling and Simulation System (DIMSS). The purpose of DIMSS is to develop and test the processes and mechanisms that facilitate ship-helicopter interface testing via man-in-the-loop ground-based flight simulators. Specifically, the DIMSS charter is to develop an accredited process for using a flight simulator to determine the wind-over-the-deck (WOD) launch and recovery flight envelope for the UH-60A ship/helicopter combination. DIMSS is a collaborative effort between the NASA Ames Research Center and OSD. OSD determines the T&E and warfighter training requirements, provides the programmatics and dynamic interface T&E experience, and conducts ship/aircraft interface tests for validating the simulation. NASA provides the research and development element, simulation facility, and simulation technical experience. This paper will highlight the benefits of the NASA/JSHIP collaboration and detail achievements of the project in terms of modeling and simulation. The Vertical Motion Simulator (VMS) at NASA Ames Research Center offers the capability to simulate a wide range of simulation cueing configurations, which include visual, aural, and body-force cueing devices. The system flexibility enables switching configurations io allow back-to-back evaluation and comparison of different levels of cueing fidelity in determining minimum training requirements. The investigation required development and integration of several major simulation system at the VMS. A new UH-60A BlackHawk interchangeable cab that provides an out-the-window (OTW) field-of-view (FOV) of 220 degrees in azimuth and 70 degrees in elevation was built. Modeling efforts involved integrating Computational Fluid Dynamics (CFD) generated data of an LHA ship airwake and integrating a real-time ship motion model developed based on a batch model from Naval Surface Warfare Center. Engineering development and integration of a three degrees-of-freedom (DOF) dynamic seat to simulate high frequency rotor-dynamics dependent motion cues for use in conjunction with the large motion system was accomplished. The development of an LHA visual model in several different levels of resolution and an aural cueing system in which three separate fidelity levels could be selected were developed. VMS also integrated a PC-based E&S simFUSION system to investigate cost effective IG alternatives. The DIMSS project consists of three phases that follow an approved Validation, Verification and accreditation (VV&A) process. The first phase will support the accreditation of the individual subsystems and models. The second will follow the verification and validation of the integrated subsystems and models, and will address fidelity requirements of the integrated models and subsystems. The third and final phase will allow the verification and validation of the full system integration. This VV&A process will address the utility of the simulated WOD launch and recovery envelope. Simulations supporting the first two stages have been completed and the data is currently being reviewed and analyzed.

Optimizing virtual reality for all users through gaze-contingent and adaptive focus displays

PubMed Central

Padmanaban, Nitish; Konrad, Robert; Stramer, Tal; Wetzstein, Gordon

2017-01-01

From the desktop to the laptop to the mobile device, personal computing platforms evolve over time. Moving forward, wearable computing is widely expected to be integral to consumer electronics and beyond. The primary interface between a wearable computer and a user is often a near-eye display. However, current generation near-eye displays suffer from multiple limitations: they are unable to provide fully natural visual cues and comfortable viewing experiences for all users. At their core, many of the issues with near-eye displays are caused by limitations in conventional optics. Current displays cannot reproduce the changes in focus that accompany natural vision, and they cannot support users with uncorrected refractive errors. With two prototype near-eye displays, we show how these issues can be overcome using display modes that adapt to the user via computational optics. By using focus-tunable lenses, mechanically actuated displays, and mobile gaze-tracking technology, these displays can be tailored to correct common refractive errors and provide natural focus cues by dynamically updating the system based on where a user looks in a virtual scene. Indeed, the opportunities afforded by recent advances in computational optics open up the possibility of creating a computing platform in which some users may experience better quality vision in the virtual world than in the real one. PMID:28193871

Circadian rhythms, time-restricted feeding, and healthy aging.

PubMed

Manoogian, Emily N C; Panda, Satchidananda

2017-10-01

Circadian rhythms optimize physiology and health by temporally coordinating cellular function, tissue function, and behavior. These endogenous rhythms dampen with age and thus compromise temporal coordination. Feeding-fasting patterns are an external cue that profoundly influence the robustness of daily biological rhythms. Erratic eating patterns can disrupt the temporal coordination of metabolism and physiology leading to chronic diseases that are also characteristic of aging. However, sustaining a robust feeding-fasting cycle, even without altering nutrition quality or quantity, can prevent or reverse these chronic diseases in experimental models. In humans, epidemiological studies have shown erratic eating patterns increase the risk of disease, whereas sustained feeding-fasting cycles, or prolonged overnight fasting, is correlated with protection from breast cancer. Therefore, optimizing the timing of external cues with defined eating patterns can sustain a robust circadian clock, which may prevent disease and improve prognosis. Copyright © 2016 Elsevier B.V. All rights reserved.

The habenula governs the attribution of incentive salience to reward predictive cues

PubMed Central

Danna, Carey L.; Shepard, Paul D.; Elmer, Greg I.

2013-01-01

The attribution of incentive salience to reward associated cues is critical for motivation and the pursuit of rewards. Disruptions in the integrity of the neural systems controlling these processes can lead to avolition and anhedonia, symptoms that cross the diagnostic boundaries of many neuropsychiatric illnesses. Here, we consider whether the habenula (Hb), a region recently demonstrated to encode negatively valenced events, also modulates the attribution of incentive salience to a neutral cue predicting a food reward. The Pavlovian autoshaping paradigm was used in the rat as an investigative tool to dissociate Pavlovian learning processes imparting strictly predictive value from learning that attributes incentive motivational value. Electrolytic lesions of the fasciculus retroflexus (fr), the sole pathway through which descending Hb efferents are conveyed, significantly increased incentive salience as measured by conditioned approaches to a cue light predictive of reward. Conversely, generation of a fictive Hb signal via fr stimulation during CS+ presentation significantly decreased the incentive salience of the predictive cue. Neither manipulation altered the reward predictive value of the cue as measured by conditioned approach to the food. Our results provide new evidence supporting a significant role for the Hb in governing the attribution of incentive motivational salience to reward predictive cues and further imply that pathological changes in Hb activity could contribute to the aberrant pursuit of debilitating goals or avolition and depression-like symptoms. PMID:24368898

Memory Reactivation during Rapid Eye Movement Sleep Promotes Its Generalization and Integration in Cortical Stores

PubMed Central

Sterpenich, Virginie; Schmidt, Christina; Albouy, Geneviève; Matarazzo, Luca; Vanhaudenhuyse, Audrey; Boveroux, Pierre; Degueldre, Christian; Leclercq, Yves; Balteau, Evelyne; Collette, Fabienne; Luxen, André; Phillips, Christophe; Maquet, Pierre

2014-01-01

Study Objectives: Memory reactivation appears to be a fundamental process in memory consolidation. In this study we tested the influence of memory reactivation during rapid eye movement (REM) sleep on memory performance and brain responses at retrieval in healthy human participants. Participants: Fifty-six healthy subjects (28 women and 28 men, age [mean ± standard deviation]: 21.6 ± 2.2 y) participated in this functional magnetic resonance imaging (fMRI) study. Methods and Results: Auditory cues were associated with pictures of faces during their encoding. These memory cues delivered during REM sleep enhanced subsequent accurate recollections but also false recognitions. These results suggest that reactivated memories interacted with semantically related representations, and induced new creative associations, which subsequently reduced the distinction between new and previously encoded exemplars. Cues had no effect if presented during stage 2 sleep, or if they were not associated with faces during encoding. Functional magnetic resonance imaging revealed that following exposure to conditioned cues during REM sleep, responses to faces during retrieval were enhanced both in a visual area and in a cortical region of multisensory (auditory-visual) convergence. Conclusions: These results show that reactivating memories during REM sleep enhances cortical responses during retrieval, suggesting the integration of recent memories within cortical circuits, favoring the generalization and schematization of the information. Citation: Sterpenich V, Schmidt C, Albouy G, Matarazzo L, Vanhaudenhuyse A, Boveroux P, Degueldre C, Leclercq Y, Balteau E, Collette F, Luxen A, Phillips C, Maquet P. Memory reactivation during rapid eye movement sleep promotes its generalization and integration in cortical stores. SLEEP 2014;37(6):1061-1075. PMID:24882901

Visual and cross-modal cues increase the identification of overlapping visual stimuli in Balint's syndrome.

PubMed

D'Imperio, Daniela; Scandola, Michele; Gobbetto, Valeria; Bulgarelli, Cristina; Salgarello, Matteo; Avesani, Renato; Moro, Valentina

2017-10-01

Cross-modal interactions improve the processing of external stimuli, particularly when an isolated sensory modality is impaired. When information from different modalities is integrated, object recognition is facilitated probably as a result of bottom-up and top-down processes. The aim of this study was to investigate the potential effects of cross-modal stimulation in a case of simultanagnosia. We report a detailed analysis of clinical symptoms and an 18 F-fluorodeoxyglucose (FDG) brain positron emission tomography/computed tomography (PET/CT) study of a patient affected by Balint's syndrome, a rare and invasive visual-spatial disorder following bilateral parieto-occipital lesions. An experiment was conducted to investigate the effects of visual and nonvisual cues on performance in tasks involving the recognition of overlapping pictures. Four modalities of sensory cues were used: visual, tactile, olfactory, and auditory. Data from neuropsychological tests showed the presence of ocular apraxia, optic ataxia, and simultanagnosia. The results of the experiment indicate a positive effect of the cues on the recognition of overlapping pictures, not only in the identification of the congruent valid-cued stimulus (target) but also in the identification of the other, noncued stimuli. All the sensory modalities analyzed (except the auditory stimulus) were efficacious in terms of increasing visual recognition. Cross-modal integration improved the patient's ability to recognize overlapping figures. However, while in the visual unimodal modality both bottom-up (priming, familiarity effect, disengagement of attention) and top-down processes (mental representation and short-term memory, the endogenous orientation of attention) are involved, in the cross-modal integration it is semantic representations that mainly activate visual recognition processes. These results are potentially useful for the design of rehabilitation training for attentional and visual-perceptual deficits.

A Bayesian Theory of Sequential Causal Learning and Abstract Transfer.

PubMed

Lu, Hongjing; Rojas, Randall R; Beckers, Tom; Yuille, Alan L

2016-03-01

Two key research issues in the field of causal learning are how people acquire causal knowledge when observing data that are presented sequentially, and the level of abstraction at which learning takes place. Does sequential causal learning solely involve the acquisition of specific cause-effect links, or do learners also acquire knowledge about abstract causal constraints? Recent empirical studies have revealed that experience with one set of causal cues can dramatically alter subsequent learning and performance with entirely different cues, suggesting that learning involves abstract transfer, and such transfer effects involve sequential presentation of distinct sets of causal cues. It has been demonstrated that pre-training (or even post-training) can modulate classic causal learning phenomena such as forward and backward blocking. To account for these effects, we propose a Bayesian theory of sequential causal learning. The theory assumes that humans are able to consider and use several alternative causal generative models, each instantiating a different causal integration rule. Model selection is used to decide which integration rule to use in a given learning environment in order to infer causal knowledge from sequential data. Detailed computer simulations demonstrate that humans rely on the abstract characteristics of outcome variables (e.g., binary vs. continuous) to select a causal integration rule, which in turn alters causal learning in a variety of blocking and overshadowing paradigms. When the nature of the outcome variable is ambiguous, humans select the model that yields the best fit with the recent environment, and then apply it to subsequent learning tasks. Based on sequential patterns of cue-outcome co-occurrence, the theory can account for a range of phenomena in sequential causal learning, including various blocking effects, primacy effects in some experimental conditions, and apparently abstract transfer of causal knowledge. Copyright © 2015 Cognitive Science Society, Inc.

Use of chemosensory cues as repellents for sea lamprey: Potential directions for population management

USGS Publications Warehouse

Imre, I.; Brown, G.E.; Bergstedt, R.A.; McDonald, R.

2010-01-01

Sea lamprey invaded the Great Lakes in the early 20th century and caused an abrupt decline in the population densities of several native fish species. The integrated management of this invasive species is composed of chemical (lampricide) applications, low-head barrier dams, adult trapping and sterile male release. Recently, there has been an increased emphasis on the development of control methods alternative to lampricide applications. We propose as an alternative-control method the use of chemosensory cues as repellents for sea lamprey population management. Based on the available evidence at this time, we suggest that injury-released chemical alarm cues show promise as repellents for sea lamprey and further research should be directed at determining whether sea lamprey show an avoidance response to these types of chemosensory cues. From a management perspective, these chemosensory cues could be used to restrict sea lamprey access to spawning grounds. Repellents could also be used together with attractants like sex pheromones to manipulate sea lamprey behavior, similar to the "push-pull" strategies utilized with insect pests. ?? 2010 Elsevier B.V.

When remembering the past suppresses memory for future actions.

PubMed

Utsumi, Kenta; Saito, Satoru

2016-01-01

Remembering planned actions at the correct time in the future is an integral component of prospective cognition. Recent studies on future remembering have led to suggestions that prospective cognition might be based on past experience. To test this hypothesis, we focused on retrieval-induced forgetting (RIF), which usually indicates that remembering past events suppresses memory for related but different past events. The current study assessed RIF in two kinds of event-based prospective memory (PM) tasks using either focal or non-focal cues for ongoing tasks. Participants studied six members from each of eight taxonomic categories and then practiced recalling three of the six members from four of the eight categories using category-stem cues. This retrieval practice suppressed the detection of non-practiced members of the practiced categories during the PM task with non-focal cues (Experiment 1) but not with focal cues (Experiment 2). The results suggest that recall of certain items inhibits the function of the others as PM cues, but only if the PM task does not largely share its processing with the ongoing task.

Extended-release naltrexone (XR-NTX) attenuates brain responses to alcohol cues in alcohol-dependent volunteers: a bold FMRI study.

PubMed

Lukas, Scott E; Lowen, Steven B; Lindsey, Kimberly P; Conn, Nina; Tartarini, Wendy; Rodolico, John; Mallya, Gopi; Palmer, Christopher; Penetar, David M

2013-09-01

Oral naltrexone reduces heavy drinking, but is less consistent as an abstinence promoter, whereas once-monthly extended-release naltrexone (XR-NTX) also maintains abstinence. The present study sought to determine if alcohol cue reactivity is attenuated by XR-NTX. Twenty-eight detoxified alcohol-dependent adult male and female volunteers received a single i.m. injection of either XR-NTX or placebo under double-blind conditions. An fMRI/cue reactivity procedure was conducted immediately before and two weeks after injection. At baseline, alcohol-related visual and olfactory cues elicited significant increases in orbital and cingulate gyri, inferior frontal and middle frontal gyri. Subsequently, brain activation was significantly altered in XR-NTX-treated individuals. These affected brain regions are associated with the integration of emotion, cognition, reward, punishment, and learning/memory, suggesting that XR-NTX attenuates the salience of alcohol-related cues. Such an effect on brain function may interrupt the processes associated with "slips" and relapse, which may account for XR-NTX's ability to maintain abstinence. Copyright © 2013 Elsevier Inc. All rights reserved.

Effects of sensorineural hearing loss on temporal coding of harmonic and inharmonic tone complexes in the auditory nerve

PubMed Central

Kale, Sushrut; Micheyl, Christophe; Heinz, Michael G.

2013-01-01

Listeners with sensorineural hearing loss (SNHL) often show poorer thresholds for fundamental-frequency (F0) discrimination, and poorer discrimination between harmonic and frequency-shifted (inharmonic) complex tones, than normal-hearing (NH) listeners—especially when these tones contain resolved or partially resolved components. It has been suggested that these perceptual deficits reflect reduced access to temporal-fine-structure (TFS) information, and could be due to degraded phase-locking in the auditory nerve (AN) with SNHL. In the present study, TFS and temporal-envelope (ENV) cues in single AN-fiber responses to bandpass-filtered harmonic and inharmonic complex tones were measured in chinchillas with either normal hearing or noise-induced SNHL. The stimuli were comparable to those used in recent psychophysical studies of F0 and harmonic/inharmonic discrimination. As in those studies, the rank of the center component was manipulated to produce different resolvability conditions, different phase relationships (cosine and random phase) were tested, and background noise was present. Neural TFS and ENV cues were quantified using cross-correlation coefficients computed using shuffled cross-correlograms between neural responses to REF (harmonic) and TEST (F0- or frequency-shifted) stimuli. In animals with SNHL, AN-fiber tuning curves showed elevated thresholds, broadened tuning, best-frequency shifts, and downward shifts in the dominant TFS response component; however, no significant degradation in the ability of AN fibers to encode TFS or ENV cues was found. Consistent with optimal-observer analyses, the results indicate that TFS and ENV cues depended only on the relevant frequency shift in Hz and thus were not degraded because phase-locking remained intact. These results suggest that perceptual “TFS-processing” deficits do not simply reflect degraded phase-locking at the level of the AN. To the extent that performance in F0 and harmonic/inharmonic discrimination tasks depend on TFS cues, it is likely through a more complicated (sub-optimal) decoding mechanism, which may involve “spatiotemporal” (place-time) neural representations. PMID:23716215

Audiovisual Temporal Perception in Aging: The Role of Multisensory Integration and Age-Related Sensory Loss

PubMed Central

Brooks, Cassandra J.; Chan, Yu Man; Anderson, Andrew J.; McKendrick, Allison M.

2018-01-01

Within each sensory modality, age-related deficits in temporal perception contribute to the difficulties older adults experience when performing everyday tasks. Since perceptual experience is inherently multisensory, older adults also face the added challenge of appropriately integrating or segregating the auditory and visual cues present in our dynamic environment into coherent representations of distinct objects. As such, many studies have investigated how older adults perform when integrating temporal information across audition and vision. This review covers both direct judgments about temporal information (the sound-induced flash illusion, temporal order, perceived synchrony, and temporal rate discrimination) and judgments regarding stimuli containing temporal information (the audiovisual bounce effect and speech perception). Although an age-related increase in integration has been demonstrated on a variety of tasks, research specifically investigating the ability of older adults to integrate temporal auditory and visual cues has produced disparate results. In this short review, we explore what factors could underlie these divergent findings. We conclude that both task-specific differences and age-related sensory loss play a role in the reported disparity in age-related effects on the integration of auditory and visual temporal information. PMID:29867415

Audiovisual Temporal Perception in Aging: The Role of Multisensory Integration and Age-Related Sensory Loss.

PubMed

Brooks, Cassandra J; Chan, Yu Man; Anderson, Andrew J; McKendrick, Allison M

2018-01-01

Within each sensory modality, age-related deficits in temporal perception contribute to the difficulties older adults experience when performing everyday tasks. Since perceptual experience is inherently multisensory, older adults also face the added challenge of appropriately integrating or segregating the auditory and visual cues present in our dynamic environment into coherent representations of distinct objects. As such, many studies have investigated how older adults perform when integrating temporal information across audition and vision. This review covers both direct judgments about temporal information (the sound-induced flash illusion, temporal order, perceived synchrony, and temporal rate discrimination) and judgments regarding stimuli containing temporal information (the audiovisual bounce effect and speech perception). Although an age-related increase in integration has been demonstrated on a variety of tasks, research specifically investigating the ability of older adults to integrate temporal auditory and visual cues has produced disparate results. In this short review, we explore what factors could underlie these divergent findings. We conclude that both task-specific differences and age-related sensory loss play a role in the reported disparity in age-related effects on the integration of auditory and visual temporal information.

mTORC1 in AGRP neurons integrates exteroceptive and interoceptive food-related cues in the modulation of adaptive energy expenditure in mice

PubMed Central

Burke, Luke K; Darwish, Tamana; Cavanaugh, Althea R; Virtue, Sam; Roth, Emma; Morro, Joanna; Liu, Shun-Mei; Xia, Jing; Dalley, Jeffrey W; Burling, Keith; Chua, Streamson; Vidal-Puig, Toni; Schwartz, Gary J; Blouet, Clémence

2017-01-01

Energy dissipation through interscapular brown adipose tissue (iBAT) thermogenesis is an important contributor to adaptive energy expenditure. However, it remains unresolved how acute and chronic changes in energy availability are detected by the brain to adjust iBAT activity and maintain energy homeostasis. Here, we provide evidence that AGRP inhibitory tone to iBAT represents an energy-sparing circuit that integrates environmental food cues and internal signals of energy availability. We establish a role for the nutrient-sensing mTORC1 signaling pathway within AGRP neurons in the detection of environmental food cues and internal signals of energy availability, and in the bi-directional control of iBAT thermogenesis during nutrient deficiency and excess. Collectively, our findings provide insights into how mTORC1 signaling within AGRP neurons surveys energy availability to engage iBAT thermogenesis, and identify AGRP neurons as a neuronal substrate for the coordination of energy intake and adaptive expenditure under varying physiological and environmental contexts. DOI: http://dx.doi.org/10.7554/eLife.22848.001 PMID:28532548

Sequential assessment of prey through the use of multiple sensory cues by an eavesdropping bat

NASA Astrophysics Data System (ADS)

Page, Rachel A.; Schnelle, Tanja; Kalko, Elisabeth K. V.; Bunge, Thomas; Bernal, Ximena E.

2012-06-01

Predators are often confronted with a broad diversity of potential prey. They rely on cues associated with prey quality and palatability to optimize their hunting success and to avoid consuming toxic prey. Here, we investigate a predator's ability to assess prey cues during capture, handling, and consumption when confronted with conflicting information about prey quality. We used advertisement calls of a preferred prey item (the túngara frog) to attract fringe-lipped bats, Trachops cirrhosus, then offered palatable, poisonous, and chemically manipulated anurans as prey. Advertisement calls elicited an attack response, but as bats approached, they used additional sensory cues in a sequential manner to update their information about prey size and palatability. While both palatable and poisonous small anurans were readily captured, large poisonous toads were approached but not contacted suggesting the use of echolocation for assessment of prey size at close range. Once prey was captured, bats used chemical cues to make final, post-capture decisions about whether to consume the prey. Bats dropped small, poisonous toads as well as palatable frogs coated in toad toxins either immediately or shortly after capture. Our study suggests that echolocation and chemical cues obtained at close range supplement information obtained from acoustic cues at long range. Updating information about prey quality minimizes the occurrence of costly errors and may be advantageous in tracking temporal and spatial fluctuations of prey and exploiting novel food sources. These findings emphasize the sequential, complex nature of prey assessment that may allow exploratory and flexible hunting behaviors.

Distributed acoustic cues for caller identity in macaque vocalization.

PubMed

Fukushima, Makoto; Doyle, Alex M; Mullarkey, Matthew P; Mishkin, Mortimer; Averbeck, Bruno B

2015-12-01

Individual primates can be identified by the sound of their voice. Macaques have demonstrated an ability to discern conspecific identity from a harmonically structured 'coo' call. Voice recognition presumably requires the integrated perception of multiple acoustic features. However, it is unclear how this is achieved, given considerable variability across utterances. Specifically, the extent to which information about caller identity is distributed across multiple features remains elusive. We examined these issues by recording and analysing a large sample of calls from eight macaques. Single acoustic features, including fundamental frequency, duration and Weiner entropy, were informative but unreliable for the statistical classification of caller identity. A combination of multiple features, however, allowed for highly accurate caller identification. A regularized classifier that learned to identify callers from the modulation power spectrum of calls found that specific regions of spectral-temporal modulation were informative for caller identification. These ranges are related to acoustic features such as the call's fundamental frequency and FM sweep direction. We further found that the low-frequency spectrotemporal modulation component contained an indexical cue of the caller body size. Thus, cues for caller identity are distributed across identifiable spectrotemporal components corresponding to laryngeal and supralaryngeal components of vocalizations, and the integration of those cues can enable highly reliable caller identification. Our results demonstrate a clear acoustic basis by which individual macaque vocalizations can be recognized.

Distributed acoustic cues for caller identity in macaque vocalization

PubMed Central

Doyle, Alex M.; Mullarkey, Matthew P.; Mishkin, Mortimer; Averbeck, Bruno B.

2015-01-01

Individual primates can be identified by the sound of their voice. Macaques have demonstrated an ability to discern conspecific identity from a harmonically structured ‘coo’ call. Voice recognition presumably requires the integrated perception of multiple acoustic features. However, it is unclear how this is achieved, given considerable variability across utterances. Specifically, the extent to which information about caller identity is distributed across multiple features remains elusive. We examined these issues by recording and analysing a large sample of calls from eight macaques. Single acoustic features, including fundamental frequency, duration and Weiner entropy, were informative but unreliable for the statistical classification of caller identity. A combination of multiple features, however, allowed for highly accurate caller identification. A regularized classifier that learned to identify callers from the modulation power spectrum of calls found that specific regions of spectral–temporal modulation were informative for caller identification. These ranges are related to acoustic features such as the call’s fundamental frequency and FM sweep direction. We further found that the low-frequency spectrotemporal modulation component contained an indexical cue of the caller body size. Thus, cues for caller identity are distributed across identifiable spectrotemporal components corresponding to laryngeal and supralaryngeal components of vocalizations, and the integration of those cues can enable highly reliable caller identification. Our results demonstrate a clear acoustic basis by which individual macaque vocalizations can be recognized. PMID:27019727

Signal relay during the life cycle of Dictyostelium.

PubMed

Mahadeo, Dana C; Parent, Carole A

2006-01-01

A fundamental property of multicellular organisms is signal relay, the process by which information is transmitted from one cell to another. The integration of external information, such as nutritional status or developmental cues, is critical to the function of organisms. In addition, the spatial organizations of multicellular organisms require intricate signal relay mechanisms. Signal relay is remarkably exhibited during the life cycle of the social amoebae Dictyostelium discoideum, a eukaryote that retains a simple way of life, yet it has greatly contributed to our knowledge of the mechanisms cells use to communicate and integrate information. This chapter focuses on the molecules and mechanisms that Dictyostelium employs during its life cycle to relay temporal and spatial cues that are required for survival.

Comparison of Classifiers for Decoding Sensory and Cognitive Information from Prefrontal Neuronal Populations

PubMed Central

Astrand, Elaine; Enel, Pierre; Ibos, Guilhem; Dominey, Peter Ford; Baraduc, Pierre; Ben Hamed, Suliann

2014-01-01

Decoding neuronal information is important in neuroscience, both as a basic means to understand how neuronal activity is related to cerebral function and as a processing stage in driving neuroprosthetic effectors. Here, we compare the readout performance of six commonly used classifiers at decoding two different variables encoded by the spiking activity of the non-human primate frontal eye fields (FEF): the spatial position of a visual cue, and the instructed orientation of the animal's attention. While the first variable is exogenously driven by the environment, the second variable corresponds to the interpretation of the instruction conveyed by the cue; it is endogenously driven and corresponds to the output of internal cognitive operations performed on the visual attributes of the cue. These two variables were decoded using either a regularized optimal linear estimator in its explicit formulation, an optimal linear artificial neural network estimator, a non-linear artificial neural network estimator, a non-linear naïve Bayesian estimator, a non-linear Reservoir recurrent network classifier or a non-linear Support Vector Machine classifier. Our results suggest that endogenous information such as the orientation of attention can be decoded from the FEF with the same accuracy as exogenous visual information. All classifiers did not behave equally in the face of population size and heterogeneity, the available training and testing trials, the subject's behavior and the temporal structure of the variable of interest. In most situations, the regularized optimal linear estimator and the non-linear Support Vector Machine classifiers outperformed the other tested decoders. PMID:24466019

Direction-dependent arm kinematics reveal optimal integration of gravity cues

PubMed Central

Gaveau, Jeremie; Berret, Bastien; Angelaki, Dora E; Papaxanthis, Charalambos

2016-01-01

The brain has evolved an internal model of gravity to cope with life in the Earth's gravitational environment. How this internal model benefits the implementation of skilled movement has remained unsolved. One prevailing theory has assumed that this internal model is used to compensate for gravity's mechanical effects on the body, such as to maintain invariant motor trajectories. Alternatively, gravity force could be used purposely and efficiently for the planning and execution of voluntary movements, thereby resulting in direction-depending kinematics. Here we experimentally interrogate these two hypotheses by measuring arm kinematics while varying movement direction in normal and zero-G gravity conditions. By comparing experimental results with model predictions, we show that the brain uses the internal model to implement control policies that take advantage of gravity to minimize movement effort. DOI: http://dx.doi.org/10.7554/eLife.16394.001 PMID:27805566

Cell-microenvironment interactions and architectures in microvascular systems

PubMed Central

Bersini, Simone; Yazdi, Iman K.; Talò, Giuseppe; Shin, Su Ryon; Moretti, Matteo; Khademhosseini, Ali

2016-01-01

In the past decade, significant advances have been made in the design and optimization of novel biomaterials and microfabrication techniques to generate vascularized tissues. Novel microfluidic systems have facilitated the development and optimization of in vitro models for exploring the complex pathophysiological phenomena that occur inside a microvascular environment. To date, most of these models have focused on engineering of increasingly complex systems, rather than analyzing the molecular and cellular mechanisms that drive microvascular network morphogenesis and remodeling. In fact, mutual interactions among endothelial cells (ECs), supporting mural cells and organ-specific cells, as well as between ECs and the extracellular matrix, are key driving forces for vascularization. This review focuses on the integration of materials science, microengineering and vascular biology for the development of in vitro microvascular systems. Various approaches currently being applied to study cell-cell/cell-matrix interactions, as well as biochemical/biophysical cues promoting vascularization and their impact on microvascular network formation, will be identified and discussed. Finally, this review will explore in vitro applications of microvascular systems, in vivo integration of transplanted vascularized tissues, and the important challenges for vascularization and controlling the microcirculatory system within the engineered tissues, especially for microfabrication approaches. It is likely that existing models and more complex models will further our understanding of the key elements of vascular network growth, stabilization and remodeling to translate basic research principles into functional, vascularized tissue constructs for regenerative medicine applications, drug screening and disease models. PMID:27417066

Cell-microenvironment interactions and architectures in microvascular systems.

PubMed

Bersini, Simone; Yazdi, Iman K; Talò, Giuseppe; Shin, Su Ryon; Moretti, Matteo; Khademhosseini, Ali

2016-11-01

In the past decade, significant advances have been made in the design and optimization of novel biomaterials and microfabrication techniques to generate vascularized tissues. Novel microfluidic systems have facilitated the development and optimization of in vitro models for exploring the complex pathophysiological phenomena that occur inside a microvascular environment. To date, most of these models have focused on engineering of increasingly complex systems, rather than analyzing the molecular and cellular mechanisms that drive microvascular network morphogenesis and remodeling. In fact, mutual interactions among endothelial cells (ECs), supporting mural cells and organ-specific cells, as well as between ECs and the extracellular matrix, are key driving forces for vascularization. This review focuses on the integration of materials science, microengineering and vascular biology for the development of in vitro microvascular systems. Various approaches currently being applied to study cell-cell/cell-matrix interactions, as well as biochemical/biophysical cues promoting vascularization and their impact on microvascular network formation, will be identified and discussed. Finally, this review will explore in vitro applications of microvascular systems, in vivo integration of transplanted vascularized tissues, and the important challenges for vascularization and controlling the microcirculatory system within the engineered tissues, especially for microfabrication approaches. It is likely that existing models and more complex models will further our understanding of the key elements of vascular network growth, stabilization and remodeling to translate basic research principles into functional, vascularized tissue constructs for regenerative medicine applications, drug screening and disease models. Copyright © 2016 Elsevier Inc. All rights reserved.

Future Targets for Female Sexual Dysfunction.

PubMed

Farmer, Melissa; Yoon, Hana; Goldstein, Irwin

2016-08-01

Female sexual function reflects a dynamic interplay of central and peripheral nervous, vascular, and endocrine systems. The primary challenge in the development of novel treatments for female sexual dysfunction is the identification and targeted modulation of excitatory sexual circuits using pharmacologic treatments that facilitate the synthesis, release, and/or receptor binding of neurochemicals, peptides, and hormones that promote female sexual function. To develop an evidence-based state-of-the-art consensus report that critically integrates current knowledge of the therapeutic potential for known molecular and cellular targets to facilitate the physiologic processes underlying female sexual function. State-of-the-art review representing the opinions of international experts developed in a consensus process during a 1-year period. Expert opinion was established by grading the evidence-based medical literature, intensive internal committee discussion, public presentation, and debate. Scientific investigation is urgently needed to expand knowledge and foster development of future treatments that maintain genital tissue integrity, enhance genital physiologic responsiveness, and optimize positive subjective appraisal of internal and external sexual cues. This article critically condenses the current knowledge of therapeutic manipulation of molecular and cellular targets within biological systems responsible for female sexual physiologic function. Future treatment targets include pharmacologic modulation of emotional learning circuits, restoration of normal tactile sensation, growth factor therapy, gene therapy, stem cell-based therapies, and regenerative medicine. Concurrent use of centrally and peripherally acting therapies could optimize treatment response. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Slow Temporal Integration Enables Robust Neural Coding and Perception of a Cue to Sound Source Location.

PubMed

Brown, Andrew D; Tollin, Daniel J

2016-09-21

In mammals, localization of sound sources in azimuth depends on sensitivity to interaural differences in sound timing (ITD) and level (ILD). Paradoxically, while typical ILD-sensitive neurons of the auditory brainstem require millisecond synchrony of excitatory and inhibitory inputs for the encoding of ILDs, human and animal behavioral ILD sensitivity is robust to temporal stimulus degradations (e.g., interaural decorrelation due to reverberation), or, in humans, bilateral clinical device processing. Here we demonstrate that behavioral ILD sensitivity is only modestly degraded with even complete decorrelation of left- and right-ear signals, suggesting the existence of a highly integrative ILD-coding mechanism. Correspondingly, we find that a majority of auditory midbrain neurons in the central nucleus of the inferior colliculus (of chinchilla) effectively encode ILDs despite complete decorrelation of left- and right-ear signals. We show that such responses can be accounted for by relatively long windows of bilateral excitatory-inhibitory interaction, which we explicitly measure using trains of narrowband clicks. Neural and behavioral data are compared with the outputs of a simple model of ILD processing with a single free parameter, the duration of excitatory-inhibitory interaction. Behavioral, neural, and modeling data collectively suggest that ILD sensitivity depends on binaural integration of excitation and inhibition within a ≳3 ms temporal window, significantly longer than observed in lower brainstem neurons. This relatively slow integration potentiates a unique role for the ILD system in spatial hearing that may be of particular importance when informative ITD cues are unavailable. In mammalian hearing, interaural differences in the timing (ITD) and level (ILD) of impinging sounds carry critical information about source location. However, natural sounds are often decorrelated between the ears by reverberation and background noise, degrading the fidelity of both ITD and ILD cues. Here we demonstrate that behavioral ILD sensitivity (in humans) and neural ILD sensitivity (in single neurons of the chinchilla auditory midbrain) remain robust under stimulus conditions that render ITD cues undetectable. This result can be explained by "slow" temporal integration arising from several-millisecond-long windows of excitatory-inhibitory interaction evident in midbrain, but not brainstem, neurons. Such integrative coding can account for the preservation of ILD sensitivity despite even extreme temporal degradations in ecological acoustic stimuli. Copyright © 2016 the authors 0270-6474/16/369908-14$15.00/0.

Piloting Systems Reset Path Integration Systems during Position Estimation

ERIC Educational Resources Information Center

Zhang, Lei; Mou, Weimin

2017-01-01

During locomotion, individuals can determine their positions with either idiothetic cues from movement (path integration systems) or visual landmarks (piloting systems). This project investigated how these 2 systems interact in determining humans' positions. In 2 experiments, participants studied the locations of 5 target objects and 1 single…

Developing Visual Creative Literacies through Integrating Art-Based Inquiry

ERIC Educational Resources Information Center

Smilan, Cathy

2016-01-01

Visual literacy and the ability to think creatively are critical skills requisite to full participation and communication in the twenty-first century. Learning experiences that integrate studio-based inquiry and other academic concepts can develop discipline skills as well as communication skills of deciphering visual cues and de/re-constructing…

Binocular and Monocular Depth Cues in Online Feedback Control of 3-D Pointing Movement

PubMed Central

Hu, Bo; Knill, David C.

2012-01-01

Previous work has shown that humans continuously use visual feedback of the hand to control goal-directed movements online. In most studies, visual error signals were predominantly in the image plane and thus were available in an observer’s retinal image. We investigate how humans use visual feedback about finger depth provided by binocular and monocular depth cues to control pointing movements. When binocularly viewing a scene in which the hand movement was made in free space, subjects were about 60 ms slower in responding to perturbations in depth than in the image plane. When monocularly viewing a scene designed to maximize the available monocular cues to finger depth (motion, changing size and cast shadows), subjects showed no response to perturbations in depth. Thus, binocular cues from the finger are critical to effective online control of hand movements in depth. An optimal feedback controller that takes into account of the low peripheral stereoacuity and inherent ambiguity in cast shadows can explain the difference in response time in the binocular conditions and lack of response in monocular conditions. PMID:21724567

Learning to integrate versus inhibiting information is modulated by age.

PubMed

Cappelletti, Marinella; Pikkat, Helen; Upstill, Emily; Speekenbrink, Maarten; Walsh, Vincent

2015-02-04

Cognitive training aiming at improving learning is often successful, but what exactly underlies the observed improvements and how these differ across the age spectrum are currently unknown. Here we asked whether learning in young and older people may reflect enhanced ability to integrate information required to perform a cognitive task or whether it may instead reflect the ability to inhibit task-irrelevant information for successful task performance. We trained 30 young and 30 aging human participants on a numerosity discrimination task known to engage the parietal cortex and in which cue-integration and inhibitory abilities can be distinguished. We coupled training with parietal, motor, or sham transcranial random noise stimulation, known for modulating neural activity. Numerosity discrimination improved after training and was maintained long term, especially in the training + parietal stimulation group, regardless of age. Despite the quantitatively similar improvement in the two age groups, the content of learning differed remarkably: aging participants improved more in inhibitory abilities, whereas younger subjects improved in cue-integration abilities. Moreover, differences in the content of learning were reflected in different transfer effects to untrained but related abilities: in the younger group, improvements in cue integration paralleled improvements in continuous quantity (time and space), whereas in the elderly group, improvements in numerosity-based inhibitory abilities generalized to other measures of inhibition and corresponded to a decline in space discrimination, possibly because conflicting learning resources are used in numerosity and continuous quantity processing. These results indicate that training can enhance different, age-dependent cognitive processes and highlight the importance of identifying the exact processes underlying learning for effective training programs. Copyright © 2015 the authors 0270-6474/15/352213-13$15.00/0.

Prediction and constraint in audiovisual speech perception.

PubMed

Peelle, Jonathan E; Sommers, Mitchell S

2015-07-01

During face-to-face conversational speech listeners must efficiently process a rapid and complex stream of multisensory information. Visual speech can serve as a critical complement to auditory information because it provides cues to both the timing of the incoming acoustic signal (the amplitude envelope, influencing attention and perceptual sensitivity) and its content (place and manner of articulation, constraining lexical selection). Here we review behavioral and neurophysiological evidence regarding listeners' use of visual speech information. Multisensory integration of audiovisual speech cues improves recognition accuracy, particularly for speech in noise. Even when speech is intelligible based solely on auditory information, adding visual information may reduce the cognitive demands placed on listeners through increasing the precision of prediction. Electrophysiological studies demonstrate that oscillatory cortical entrainment to speech in auditory cortex is enhanced when visual speech is present, increasing sensitivity to important acoustic cues. Neuroimaging studies also suggest increased activity in auditory cortex when congruent visual information is available, but additionally emphasize the involvement of heteromodal regions of posterior superior temporal sulcus as playing a role in integrative processing. We interpret these findings in a framework of temporally-focused lexical competition in which visual speech information affects auditory processing to increase sensitivity to acoustic information through an early integration mechanism, and a late integration stage that incorporates specific information about a speaker's articulators to constrain the number of possible candidates in a spoken utterance. Ultimately it is words compatible with both auditory and visual information that most strongly determine successful speech perception during everyday listening. Thus, audiovisual speech perception is accomplished through multiple stages of integration, supported by distinct neuroanatomical mechanisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cue-specific effects of categorization training on the relative weighting of acoustic cues to consonant voicing in English

PubMed Central

Francis, Alexander L.; Kaganovich, Natalya; Driscoll-Huber, Courtney

2008-01-01

In English, voiced and voiceless syllable-initial stop consonants differ in both fundamental frequency at the onset of voicing (onset F0) and voice onset time (VOT). Although both correlates, alone, can cue the voicing contrast, listeners weight VOT more heavily when both are available. Such differential weighting may arise from differences in the perceptual distance between voicing categories along the VOT versus onset F0 dimensions, or it may arise from a bias to pay more attention to VOT than to onset F0. The present experiment examines listeners’ use of these two cues when classifying stimuli in which perceptual distance was artificially equated along the two dimensions. Listeners were also trained to categorize stimuli based on one cue at the expense of another. Equating perceptual distance eliminated the expected bias toward VOT before training, but successfully learning to base decisions more on VOT and less on onset F0 was easier than vice versa. Perceptual distance along both dimensions increased for both groups after training, but only VOT-trained listeners showed a decrease in Garner interference. Results lend qualified support to an attentional model of phonetic learning in which learning involves strategic redeployment of selective attention across integral acoustic cues. PMID:18681610

Biasing spatial attention with semantic information: an event coding approach.

PubMed

Amer, Tarek; Gozli, Davood G; Pratt, Jay

2017-04-21

We investigated the influence of conceptual processing on visual attention from the standpoint of Theory of Event Coding (TEC). The theory makes two predictions: first, an important factor in determining the influence of event 1 on processing event 2 is whether features of event 1 are bound into a unified representation (i.e., selection or retrieval of event 1). Second, whether processing the two events facilitates or interferes with each other should depend on the extent to which their constituent features overlap. In two experiments, participants performed a visual-attention cueing task, in which the visual target (event 2) was preceded by a relevant or irrelevant explicit (e.g., "UP") or implicit (e.g., "HAPPY") spatial-conceptual cue (event 1). Consistent with TEC, we found relevant explicit cues (which featurally overlap to a greater extent with the target) and implicit cues (which featurally overlap to a lesser extent), respectively, facilitated and interfered with target processing at compatible locations. Irrelevant explicit and implicit cues, on the other hand, both facilitated target processing, presumably because they were less likely selected or retrieved as an integrated and unified event file. We argue that such effects, often described as "attentional cueing", are better accounted for within the event coding framework.

Modular extracellular sensor architecture for engineering mammalian cell-based devices.

PubMed

Daringer, Nichole M; Dudek, Rachel M; Schwarz, Kelly A; Leonard, Joshua N

2014-12-19

Engineering mammalian cell-based devices that monitor and therapeutically modulate human physiology is a promising and emerging frontier in clinical synthetic biology. However, realizing this vision will require new technologies enabling engineered circuitry to sense and respond to physiologically relevant cues. No existing technology enables an engineered cell to sense exclusively extracellular ligands, including proteins and pathogens, without relying upon native cellular receptors or signal transduction pathways that may be subject to crosstalk with native cellular components. To address this need, we here report a technology we term a Modular Extracellular Sensor Architecture (MESA). This self-contained receptor and signal transduction platform is maximally orthogonal to native cellular processes and comprises independent, tunable protein modules that enable performance optimization and straightforward engineering of novel MESA that recognize novel ligands. We demonstrate ligand-inducible activation of MESA signaling, optimization of receptor performance using design-based approaches, and generation of MESA biosensors that produce outputs in the form of either transcriptional regulation or transcription-independent reconstitution of enzymatic activity. This systematic, quantitative platform characterization provides a framework for engineering MESA to recognize novel ligands and for integrating these sensors into diverse mammalian synthetic biology applications.

Joint attention enhances visual working memory.

PubMed

Gregory, Samantha E A; Jackson, Margaret C

2017-02-01

Joint attention-the mutual focus of 2 individuals on an item-speeds detection and discrimination of target information. However, what happens to that information beyond the initial perceptual episode? To fully comprehend and engage with our immediate environment also requires working memory (WM), which integrates information from second to second to create a coherent and fluid picture of our world. Yet, no research exists at present that examines how joint attention directly impacts WM. To investigate this, we created a unique paradigm that combines gaze cues with a traditional visual WM task. A central, direct gaze 'cue' face looked left or right, followed 500 ms later by 4, 6, or 8 colored squares presented on one side of the face for encoding. Crucially, the cue face either looked at the squares (valid cue) or looked away from them (invalid cue). A no shift (direct gaze) condition served as a baseline. After a blank 1,000 ms maintenance interval, participants stated whether a single test square color was present or not in the preceding display. WM accuracy was significantly greater for colors encoded in the valid versus invalid and direct conditions. Further experiments showed that an arrow cue and a low-level motion cue-both shown to reliably orient attention-did not reliably modulate WM, indicating that social cues are more powerful. This study provides the first direct evidence that sharing the focus of another individual establishes a point of reference from which information is advantageously encoded into WM. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Instant transformation of learned repulsion into motivational "wanting".

PubMed

Robinson, Mike J F; Berridge, Kent C

2013-02-18

Learned cues for pleasant reward often elicit desire, which, in addicts, may become compulsive. According to the dominant view in addiction neuroscience and reinforcement modeling, such desires are the simple products of learning, coming from a past association with reward outcome. We demonstrate that cravings are more than merely the products of accumulated pleasure memories-even a repulsive learned cue for unpleasantness can become suddenly desired via the activation of mesocorticolimbic circuitry. Rats learned repulsion toward a Pavlovian cue (a briefly-inserted metal lever) that always predicted an unpleasant Dead Sea saltiness sensation. Yet, upon first reencounter in a novel sodium-depletion state to promote mesocorticolimbic reactivity (reflected by elevated Fos activation in ventral tegmentum, nucleus accumbens, ventral pallidum, and the orbitofrontal prefrontal cortex), the learned cue was instantly transformed into an attractive and powerful motivational magnet. Rats jumped and gnawed on the suddenly attractive Pavlovian lever cue, despite never having tasted intense saltiness as anything other than disgusting. Instant desire transformation of a learned cue contradicts views that Pavlovian desires are essentially based on previously learned values (e.g., prediction error or temporal difference models). Instead desire is recomputed at reencounter by integrating Pavlovian information with the current brain/physiological state. This powerful brain transformation reverses strong learned revulsion into avid attraction. When applied to addiction, related mesocorticolimbic transformations (e.g., drugs or neural sensitization) of cues for already-pleasant drug experiences could create even more intense cravings. This cue/state transformation helps define what it means to say that addiction hijacks brain limbic circuits of natural reward. Copyright © 2013 Elsevier Ltd. All rights reserved.

Clinical judgments about endotracheal suctioning: what cues do expert pediatric critical care nurses consider?

PubMed

Thomas, Margot; Fothergill-Bourbonnais, Frances

2005-12-01

Making accurate and timely judgments based on multiple ways of knowing is an essential skill in critical care nursing practice. Studies have proposed that positive patient outcomes are linked to expert judgments in a variety of critical care situations; however, little is known about clinical judgments related to specific critical care nursing interventions. This article presents a qualitative nursing research study which examined the cues that expert pediatric critical care nurses used in making clinical judgments about suctioning intubated and ventilated, critically ill children. The participants' words and actions attest that the 'sensing' and 'thinking' of the process of cue use, are interwoven with, and integral to, the 'doing,' which is the process of skilled performance.

Integration of a vision-based tracking platform, visual instruction, and error analysis models for an efficient billiard training system

NASA Astrophysics Data System (ADS)

Shih, Chihhsiong; Hsiung, Pao-Ann; Wan, Chieh-Hao; Koong, Chorng-Shiuh; Liu, Tang-Kun; Yang, Yuanfan; Lin, Chu-Hsing; Chu, William Cheng-Chung

2009-02-01

A billiard ball tracking system is designed to combine with a visual guide interface to instruct users for a reliable strike. The integrated system runs on a PC platform. The system makes use of a vision system for cue ball, object ball and cue stick tracking. A least-squares error calibration process correlates the real-world and the virtual-world pool ball coordinates for a precise guidance line calculation. Users are able to adjust the cue stick on the pool table according to a visual guidance line instruction displayed on a PC monitor. The ideal visual guidance line extended from the cue ball is calculated based on a collision motion analysis. In addition to calculating the ideal visual guide, the factors influencing selection of the best shot among different object balls and pockets are explored. It is found that a tolerance angle around the ideal line for the object ball to roll into a pocket determines the difficulty of a strike. This angle depends in turn on the distance from the pocket to the object, the distance from the object to the cue ball, and the angle between these two vectors. Simulation results for tolerance angles as a function of these quantities are given. A selected object ball was tested extensively with respect to various geometrical parameters with and without using our integrated system. Players with different proficiency levels were selected for the experiment. The results indicate that all players benefit from our proposed visual guidance system in enhancing their skills, while low-skill players show the maximum enhancement in skill with the help of our system. All exhibit enhanced maximum and average hit-in rates. Experimental results on hit-in rates have shown a pattern consistent with that of the analysis. The hit-in rate is thus tightly connected with the analyzed tolerance angles for sinking object balls into a target pocket. These results prove the efficiency of our system, and the analysis results can be used to attain an efficient game-playing strategy.

Larval Settlement: The Role of Surface Topography for Sessile Coral Reef Invertebrates

PubMed Central

Whalan, Steve; Abdul Wahab, Muhammad A.; Sprungala, Susanne; Poole, Andrew J.; de Nys, Rocky

2015-01-01

For sessile marine invertebrates with complex life cycles, habitat choice is directed by the larval phase. Defining which habitat-linked cues are implicated in sessile invertebrate larval settlement has largely concentrated on chemical cues which are thought to signal optimal habitat. There has been less effort establishing physical settlement cues, including the role of surface microtopography. This laboratory based study tested whether surface microtopography alone (without chemical cues) plays an important contributing role in the settlement of larvae of coral reef sessile invertebrates. We measured settlement to tiles, engineered with surface microtopography (holes) that closely matched the sizes (width) of larvae of a range of corals and sponges, in addition to surfaces with holes that were markedly larger than larvae. Larvae from two species of scleractinian corals (Acropora millepora and Ctenactis crassa) and three species of coral reef sponges (Luffariella variabilis, Carteriospongia foliascens and Ircinia sp.,) were used in experiments. L. variabilis, A. millepora and C. crassa showed markedly higher settlement to surface microtopography that closely matched their larval width. C. foliascens and Ircinia sp., showed no specificity to surface microtopography, settling just as often to microtopography as to flat surfaces. The findings of this study question the sole reliance on chemical based larval settlement cues, previously established for some coral and sponge species, and demonstrate that specific physical cues (surface complexity) can also play an important role in larval settlement of coral reef sessile invertebrates. PMID:25671562

Top-down controlled alpha band activity in somatosensory areas determines behavioral performance in a discrimination task.

PubMed

Haegens, Saskia; Händel, Barbara F; Jensen, Ole

2011-04-06

The brain receives a rich flow of information which must be processed according to behavioral relevance. How is the state of the sensory system adjusted to up- or downregulate processing according to anticipation? We used magnetoencephalography to investigate whether prestimulus alpha band activity (8-14 Hz) reflects allocation of attentional resources in the human somatosensory system. Subjects performed a tactile discrimination task where a visual cue directed attention to their right or left hand. The strength of attentional modulation was controlled by varying the reliability of the cue in three experimental blocks (100%, 75%, or 50% valid cueing). While somatosensory prestimulus alpha power lateralized strongly with a fully predictive cue (100%), lateralization was decreased with lower cue reliability (75%) and virtually absent if the cue had no predictive value at all (50%). Importantly, alpha lateralization influenced the subjects' behavioral performance positively: both accuracy and speed of response improved with the degree of alpha lateralization. This study demonstrates that prestimulus alpha lateralization in the somatosensory system behaves similarly to posterior alpha activity observed in visual attention tasks. Our findings extend the notion that alpha band activity is involved in shaping the functional architecture of the working brain by determining both the engagement and disengagement of specific regions: the degree of anticipation modulates the alpha activity in sensory regions in a graded manner. Thus, the alpha activity is under top-down control and seems to play an important role for setting the state of sensory regions to optimize processing.

Larval settlement: the role of surface topography for sessile coral reef invertebrates.

PubMed

Whalan, Steve; Wahab, Muhammad A Abdul; Sprungala, Susanne; Poole, Andrew J; de Nys, Rocky

2015-01-01

For sessile marine invertebrates with complex life cycles, habitat choice is directed by the larval phase. Defining which habitat-linked cues are implicated in sessile invertebrate larval settlement has largely concentrated on chemical cues which are thought to signal optimal habitat. There has been less effort establishing physical settlement cues, including the role of surface microtopography. This laboratory based study tested whether surface microtopography alone (without chemical cues) plays an important contributing role in the settlement of larvae of coral reef sessile invertebrates. We measured settlement to tiles, engineered with surface microtopography (holes) that closely matched the sizes (width) of larvae of a range of corals and sponges, in addition to surfaces with holes that were markedly larger than larvae. Larvae from two species of scleractinian corals (Acropora millepora and Ctenactis crassa) and three species of coral reef sponges (Luffariella variabilis, Carteriospongia foliascens and Ircinia sp.,) were used in experiments. L. variabilis, A. millepora and C. crassa showed markedly higher settlement to surface microtopography that closely matched their larval width. C. foliascens and Ircinia sp., showed no specificity to surface microtopography, settling just as often to microtopography as to flat surfaces. The findings of this study question the sole reliance on chemical based larval settlement cues, previously established for some coral and sponge species, and demonstrate that specific physical cues (surface complexity) can also play an important role in larval settlement of coral reef sessile invertebrates.

A New View on an Old Debate: Type of Cue-Conflict Manipulation and Availability of Stars Can Explain the Discrepancies between Cue-Calibration Experiments with Migratory Songbirds.

PubMed

Sjöberg, Sissel; Muheim, Rachel

2016-01-01

Migratory birds use multiple compass systems for orientation, including a magnetic, star and sun/polarized light compass. To keep these compasses in register, birds have to regularly update them with respect to a common reference. However, cue-conflict studies have revealed contradictory results on the compass hierarchy, favoring either celestial or magnetic compass cues as the primary calibration reference. Both the geomagnetic field and polarized light cues present at sunrise and sunset have been shown to play a role in compass cue integration, and evidence suggests that polarized light cues at sunrise and sunset may provide the primary calibration reference for the other compass systems. We tested whether migratory garden warblers recalibrated their compasses when they were exposed to the natural celestial cues at sunset in a shifted magnetic field, which are conditions that have been shown to be necessary for the use of a compass reference based on polarized light cues. We released the birds on the same evening under a starry sky and followed them by radio tracking. We found no evidence of compass recalibration, even though the birds had a full view of polarized light cues near the horizon at sunset during the cue-conflict exposure. Based on a meta-analysis of the available literature, we propose an extended unifying theory on compass cue hierarchy used by migratory birds to calibrate the different compasses. According to this scheme, birds recalibrate their magnetic compass by sunrise/sunset polarized light cues, provided they have access to the vertically aligned band of maximum polarization near the horizon and a view of landmarks. Once the stars appear in the sky, the birds then recalibrate the star compass with respect of the recalibrated magnetic compass. If sunrise and sunset information can be viewed from the same location, the birds average the information to get a true geographic reference. If polarized light information is not available near the horizon at sunrise or sunset, the birds temporarily transfer the previously calibrated magnetic compass information to the available celestial compasses. We conclude that the type of cue-conflict manipulation and the availability of stars can explain the discrepancies between studies.

A New View on an Old Debate: Type of Cue-Conflict Manipulation and Availability of Stars Can Explain the Discrepancies between Cue-Calibration Experiments with Migratory Songbirds

PubMed Central

Sjöberg, Sissel; Muheim, Rachel

2016-01-01

Migratory birds use multiple compass systems for orientation, including a magnetic, star and sun/polarized light compass. To keep these compasses in register, birds have to regularly update them with respect to a common reference. However, cue-conflict studies have revealed contradictory results on the compass hierarchy, favoring either celestial or magnetic compass cues as the primary calibration reference. Both the geomagnetic field and polarized light cues present at sunrise and sunset have been shown to play a role in compass cue integration, and evidence suggests that polarized light cues at sunrise and sunset may provide the primary calibration reference for the other compass systems. We tested whether migratory garden warblers recalibrated their compasses when they were exposed to the natural celestial cues at sunset in a shifted magnetic field, which are conditions that have been shown to be necessary for the use of a compass reference based on polarized light cues. We released the birds on the same evening under a starry sky and followed them by radio tracking. We found no evidence of compass recalibration, even though the birds had a full view of polarized light cues near the horizon at sunset during the cue-conflict exposure. Based on a meta-analysis of the available literature, we propose an extended unifying theory on compass cue hierarchy used by migratory birds to calibrate the different compasses. According to this scheme, birds recalibrate their magnetic compass by sunrise/sunset polarized light cues, provided they have access to the vertically aligned band of maximum polarization near the horizon and a view of landmarks. Once the stars appear in the sky, the birds then recalibrate the star compass with respect of the recalibrated magnetic compass. If sunrise and sunset information can be viewed from the same location, the birds average the information to get a true geographic reference. If polarized light information is not available near the horizon at sunrise or sunset, the birds temporarily transfer the previously calibrated magnetic compass information to the available celestial compasses. We conclude that the type of cue-conflict manipulation and the availability of stars can explain the discrepancies between studies. PMID:26941631

The extraction and integration framework: a two-process account of statistical learning.

PubMed

Thiessen, Erik D; Kronstein, Alexandra T; Hufnagle, Daniel G

2013-07-01

The term statistical learning in infancy research originally referred to sensitivity to transitional probabilities. Subsequent research has demonstrated that statistical learning contributes to infant development in a wide array of domains. The range of statistical learning phenomena necessitates a broader view of the processes underlying statistical learning. Learners are sensitive to a much wider range of statistical information than the conditional relations indexed by transitional probabilities, including distributional and cue-based statistics. We propose a novel framework that unifies learning about all of these kinds of statistical structure. From our perspective, learning about conditional relations outputs discrete representations (such as words). Integration across these discrete representations yields sensitivity to cues and distributional information. To achieve sensitivity to all of these kinds of statistical structure, our framework combines processes that extract segments of the input with processes that compare across these extracted items. In this framework, the items extracted from the input serve as exemplars in long-term memory. The similarity structure of those exemplars in long-term memory leads to the discovery of cues and categorical structure, which guides subsequent extraction. The extraction and integration framework provides a way to explain sensitivity to both conditional statistical structure (such as transitional probabilities) and distributional statistical structure (such as item frequency and variability), and also a framework for thinking about how these different aspects of statistical learning influence each other. 2013 APA, all rights reserved

Stoichiometry of microbial carbon use efficiency in soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinsabaugh, Robert L.; Turner, Benjamin L.; Talbot, Jennifer M.

The carbon use efficiency (CUE) of microbial communities partitions the flow of C from primary producers to the atmosphere, decomposer food webs, and soil C stores. CUE, usually defined as the ratio of growth to assimilation, is a critical parameter in ecosystem models, but is seldom measured directly in soils because of the methodological difficulty of measuring in situ rates of microbial growth and respiration. Alternatively, CUE can be estimated indirectly from the elemental stoichiometry of organic matter and microbial biomass, and the ratios of C to nutrient-acquiring ecoenzymatic activities. In this paper, we used this approach to estimate andmore » compare microbial CUE in >2000 soils from a broad range of ecosystems. Mean CUE based on C:N stoichiometry was 0.269 ± 0.110 (mean ± SD). A parallel calculation based on C:P stoichiometry yielded a mean CUE estimate of 0.252 ± 0.125. The mean values and frequency distributions were similar to those from aquatic ecosystems, also calculated from stoichiometric models, and to those calculated from direct measurements of bacterial and fungal growth and respiration. CUE was directly related to microbial biomass C with a scaling exponent of 0.304 (95% CI 0.237–0.371) and inversely related to microbial biomass P with a scaling exponent of -0.234 (95% CI -0.289 to -0.179). Relative to CUE, biomass specific turnover time increased with a scaling exponent of 0.509 (95% CI 0.467–0.551). CUE increased weakly with mean annual temperature. CUE declined with increasing soil pH reaching a minimum at pH 7.0, then increased again as soil pH approached 9.0, a pattern consistent with pH trends in the ratio of fungal : bacteria abundance and growth. Structural equation models that related geographic variables to CUE component variables showed the strongest connections for paths linking latitude and pH to β-glucosidase activity and soil C:N:P ratios. Finally, the integration of stoichiometric and metabolic models provides a quantitative description of the functional organization of soil microbial communities that can improve the representation of CUE in microbial process and ecosystem simulation models.« less

Stoichiometry of microbial carbon use efficiency in soils

DOE PAGES

Sinsabaugh, Robert L.; Turner, Benjamin L.; Talbot, Jennifer M.; ...

2016-03-23

The carbon use efficiency (CUE) of microbial communities partitions the flow of C from primary producers to the atmosphere, decomposer food webs, and soil C stores. CUE, usually defined as the ratio of growth to assimilation, is a critical parameter in ecosystem models, but is seldom measured directly in soils because of the methodological difficulty of measuring in situ rates of microbial growth and respiration. Alternatively, CUE can be estimated indirectly from the elemental stoichiometry of organic matter and microbial biomass, and the ratios of C to nutrient-acquiring ecoenzymatic activities. In this paper, we used this approach to estimate andmore » compare microbial CUE in >2000 soils from a broad range of ecosystems. Mean CUE based on C:N stoichiometry was 0.269 ± 0.110 (mean ± SD). A parallel calculation based on C:P stoichiometry yielded a mean CUE estimate of 0.252 ± 0.125. The mean values and frequency distributions were similar to those from aquatic ecosystems, also calculated from stoichiometric models, and to those calculated from direct measurements of bacterial and fungal growth and respiration. CUE was directly related to microbial biomass C with a scaling exponent of 0.304 (95% CI 0.237–0.371) and inversely related to microbial biomass P with a scaling exponent of -0.234 (95% CI -0.289 to -0.179). Relative to CUE, biomass specific turnover time increased with a scaling exponent of 0.509 (95% CI 0.467–0.551). CUE increased weakly with mean annual temperature. CUE declined with increasing soil pH reaching a minimum at pH 7.0, then increased again as soil pH approached 9.0, a pattern consistent with pH trends in the ratio of fungal : bacteria abundance and growth. Structural equation models that related geographic variables to CUE component variables showed the strongest connections for paths linking latitude and pH to β-glucosidase activity and soil C:N:P ratios. Finally, the integration of stoichiometric and metabolic models provides a quantitative description of the functional organization of soil microbial communities that can improve the representation of CUE in microbial process and ecosystem simulation models.« less

Musicians have enhanced audiovisual multisensory binding: experience-dependent effects in the double-flash illusion.

PubMed

Bidelman, Gavin M

2016-10-01

Musical training is associated with behavioral and neurophysiological enhancements in auditory processing for both musical and nonmusical sounds (e.g., speech). Yet, whether the benefits of musicianship extend beyond enhancements to auditory-specific skills and impact multisensory (e.g., audiovisual) processing has yet to be fully validated. Here, we investigated multisensory integration of auditory and visual information in musicians and nonmusicians using a double-flash illusion, whereby the presentation of multiple auditory stimuli (beeps) concurrent with a single visual object (flash) induces an illusory perception of multiple flashes. We parametrically varied the onset asynchrony between auditory and visual events (leads and lags of ±300 ms) to quantify participants' "temporal window" of integration, i.e., stimuli in which auditory and visual cues were fused into a single percept. Results show that musically trained individuals were both faster and more accurate at processing concurrent audiovisual cues than their nonmusician peers; nonmusicians had a higher susceptibility for responding to audiovisual illusions and perceived double flashes over an extended range of onset asynchronies compared to trained musicians. Moreover, temporal window estimates indicated that musicians' windows (<100 ms) were ~2-3× shorter than nonmusicians' (~200 ms), suggesting more refined multisensory integration and audiovisual binding. Collectively, findings indicate a more refined binding of auditory and visual cues in musically trained individuals. We conclude that experience-dependent plasticity of intensive musical experience extends beyond simple listening skills, improving multimodal processing and the integration of multiple sensory systems in a domain-general manner.

Neurite outgrowth at the interface of 2D and 3D growth environments

NASA Astrophysics Data System (ADS)

Kofron, Celinda M.; Fong, Vivian J.; Hoffman-Kim, Diane

2009-02-01

Growing neurons navigate complex environments, but in vitro systems for studying neuronal growth typically limit the cues to flat surfaces or a single type of cue, thereby limiting the resulting growth. Here we examined the growth of neurons presented with two-dimensional (2D) substrate-bound cues when these cues were presented in conjunction with a more complex three-dimensional (3D) architecture. Dorsal root ganglia (DRG) explants were cultured at the interface between a collagen I matrix and a glass coverslip. Laminin (LN) or chondroitin sulfate proteoglycans (CSPG) were uniformly coated on the surface of the glass coverslip or patterned in 50 µm tracks by microcontact printing. Quantitative analysis of neurite outgrowth with a novel grid system at multiple depths in the gel revealed several interesting trends. Most of the neurites extended at the surface of the gel when LN was presented whereas more neurites extended into the gel when CSPG was presented. Patterning of cues did not affect neurite density or depth of growth. However, neurite outgrowth near the surface of the gel aligned with LN patterns, and these extensions were significantly longer than neurites extended in other cultures. In interface cultures, DRG growth patterns varied with the type of cue where neurite density was higher in cultures presenting LN than in cultures presenting CSPG. These results represent an important step toward understanding how neurons integrate local structural and chemical cues to make net growth decisions.

Toward bridging the gap between biological, psychobiological and psychosocial models of alcohol craving.

PubMed

Monti, P M; Rohsenow, D J; Hutchison, K E

2000-08-01

Urge to drink ("craving") has been a central focus of many theories and treatments, but some researchers question the importance of urges during recovery. Several studies assessed reactions to the presence of beverage alcohol (cue-reactivity) or to simulated high-risk situations (role plays). Higher urges in response to role plays predicted more drinking during the 6 months after treatment. However, urges in response to beverage cues were inconsistently predictive of outcome while measures of awareness or attention to cues predicted less drinking. Urge to drink might reflect a conflict between motivation to drink and awareness of danger. Whether urges predict increased risk of drinking should be a function of factors that affect motivation to drink, awareness of risk and effectiveness of coping. Cue-reactivity assessment has recently been used to bridge the gap between psychosocial and biomedical approaches in several ways: (1) salivation to cues predicts increased drinking independent of urge or attention, showing the value of including both physiological and psychosocial measures; (2) naltrexone has been shown to decrease cue-elicited urge to drink, illustrating the value of this assessment methodology for medications evaluation and (3) pre-pulse inhibition of startle response is being used to investigate the role of dopaminergic pathways in cue-elicited urge. Thus, this laboratory based program of research has the potential to add to knowledge of both biomedical and psychosocial mechanisms involved in urge and relapse, leading to greater integration of models.

The Function of Consciousness in Multisensory Integration

ERIC Educational Resources Information Center

Palmer, Terry D.; Ramsey, Ashley K.

2012-01-01

The function of consciousness was explored in two contexts of audio-visual speech, cross-modal visual attention guidance and McGurk cross-modal integration. Experiments 1, 2, and 3 utilized a novel cueing paradigm in which two different flash suppressed lip-streams cooccured with speech sounds matching one of these streams. A visual target was…

Development of Multisensory Spatial Integration and Perception in Humans

ERIC Educational Resources Information Center

Neil, Patricia A.; Chee-Ruiter, Christine; Scheier, Christian; Lewkowicz, David J.; Shimojo, Shinsuke

2006-01-01

Previous studies have shown that adults respond faster and more reliably to bimodal compared to unimodal localization cues. The current study investigated for the first time the development of audiovisual (A-V) integration in spatial localization behavior in infants between 1 and 10 months of age. We observed infants' head and eye movements in…

Effects of preparation time and trial type probability on performance of anti- and pro-saccades.

PubMed

Pierce, Jordan E; McDowell, Jennifer E

2016-02-01

Cognitive control optimizes responses to relevant task conditions by balancing bottom-up stimulus processing with top-down goal pursuit. It can be investigated using the ocular motor system by contrasting basic prosaccades (look toward a stimulus) with complex antisaccades (look away from a stimulus). Furthermore, the amount of time allotted between trials, the need to switch task sets, and the time allowed to prepare for an upcoming saccade all impact performance. In this study the relative probabilities of anti- and pro-saccades were manipulated across five blocks of interleaved trials, while the inter-trial interval and trial type cue duration were varied across subjects. Results indicated that inter-trial interval had no significant effect on error rates or reaction times (RTs), while a shorter trial type cue led to more antisaccade errors and faster overall RTs. Responses following a shorter cue duration also showed a stronger effect of trial type probability, with more antisaccade errors in blocks with a low antisaccade probability and slower RTs for each saccade task when its trial type was unlikely. A longer cue duration yielded fewer errors and slower RTs, with a larger switch cost for errors compared to a short cue duration. Findings demonstrated that when the trial type cue duration was shorter, visual motor responsiveness was faster and subjects relied upon the implicit trial probability context to improve performance. When the cue duration was longer, increased fixation-related activity may have delayed saccade motor preparation and slowed responses, guiding subjects to respond in a controlled manner regardless of trial type probability. Copyright © 2016 Elsevier B.V. All rights reserved.

Field Assessment of the Predation Risk - Food Availability Trade-Off in Crab Megalopae Settlement

PubMed Central

Tapia-Lewin, Sebastián; Pardo, Luis Miguel

2014-01-01

Settlement is a key process for meroplanktonic organisms as it determines distribution of adult populations. Starvation and predation are two of the main mortality causes during this period; therefore, settlement tends to be optimized in microhabitats with high food availability and low predator density. Furthermore, brachyuran megalopae actively select favorable habitats for settlement, via chemical, visual and/or tactile cues. The main objective in this study was to assess the settlement of Metacarcinus edwardsii and Cancer plebejus under different combinations of food availability levels and predator presence. We determined, in the field, which factor is of greater relative importance when choosing a suitable microhabitat for settling. Passive larval collectors were deployed, crossing different scenarios of food availability and predator presence. We also explore if megalopae actively choose predator-free substrates in response to visual and/or chemical cues. We tested the response to combined visual and chemical cues and to each individually. Data was tested using a two-way factorial design ANOVA. In both species, food did not cause significant effect on settlement success, but predator presence did, therefore there was not trade-off in this case and megalopae respond strongly to predation risk by active aversion. Larvae of M. edwardsii responded to chemical and visual cues simultaneously, but there was no response to either cue by itself. Statistically, C. plebejus did not exhibit a differential response to cues, but reacted with a strong similar tendency as M. edwardsii. We concluded that crab megalopae actively select predator-free microhabitat, independently of food availability, using chemical and visual cues combined. The findings in this study highlight the great relevance of predation on the settlement process and recruitment of marine invertebrates with complex life cycles. PMID:24748151

Cultural differences in on-line sensitivity to emotional voices: comparing East and West

PubMed Central

Liu, Pan; Rigoulot, Simon; Pell, Marc D.

2015-01-01

Evidence that culture modulates on-line neural responses to the emotional meanings encoded by vocal and facial expressions was demonstrated recently in a study comparing English North Americans and Chinese (Liu et al., 2015). Here, we compared how individuals from these two cultures passively respond to emotional cues from faces and voices using an Oddball task. Participants viewed in-group emotional faces, with or without simultaneous vocal expressions, while performing a face-irrelevant visual task as the EEG was recorded. A significantly larger visual Mismatch Negativity (vMMN) was observed for Chinese vs. English participants when faces were accompanied by voices, suggesting that Chinese were influenced to a larger extent by task-irrelevant vocal cues. These data highlight further differences in how adults from East Asian vs. Western cultures process socio-emotional cues, arguing that distinct cultural practices in communication (e.g., display rules) shape neurocognitive activity associated with the early perception and integration of multi-sensory emotional cues. PMID:26074808

A nerve guidance conduit with topographical and biochemical cues: potential application using human neural stem cells

NASA Astrophysics Data System (ADS)

Jenkins, Phillip M.; Laughter, Melissa R.; Lee, David J.; Lee, Young M.; Freed, Curt R.; Park, Daewon

2015-06-01

Despite major advances in the pathophysiological understanding of peripheral nerve damage, the treatment of nerve injuries still remains an unmet medical need. Nerve guidance conduits present a promising treatment option by providing a growth-permissive environment that 1) promotes neuronal cell survival and axon growth and 2) directs axonal extension. To this end, we designed an electrospun nerve guidance conduit using a blend of polyurea and poly-caprolactone with both biochemical and topographical cues. Biochemical cues were integrated into the conduit by functionalizing the polyurea with RGD to improve cell attachment. Topographical cues that resemble natural nerve tissue were incorporated by introducing intraluminal microchannels aligned with nanofibers. We determined that electrospinning the polymer solution across a two electrode system with dissolvable sucrose fibers produced a polymer conduit with the appropriate biomimetic properties. Human neural stem cells were cultured on the conduit to evaluate its ability to promote neuronal growth and axonal extension. The nerve guidance conduit was shown to enhance cell survival, migration, and guide neurite extension.

Bayesian modeling of cue interaction: bistability in stereoscopic slant perception.

PubMed

van Ee, Raymond; Adams, Wendy J; Mamassian, Pascal

2003-07-01

Our two eyes receive different views of a visual scene, and the resulting binocular disparities enable us to reconstruct its three-dimensional layout. However, the visual environment is also rich in monocular depth cues. We examined the resulting percept when observers view a scene in which there are large conflicts between the surface slant signaled by binocular disparities and the slant signaled by monocular perspective. For a range of disparity-perspective cue conflicts, many observers experience bistability: They are able to perceive two distinct slants and to flip between the two percepts in a controlled way. We present a Bayesian model that describes the quantitative aspects of perceived slant on the basis of the likelihoods of both perspective and disparity slant information combined with prior assumptions about the shape and orientation of objects in the scene. Our Bayesian approach can be regarded as an overarching framework that allows researchers to study all cue integration aspects-including perceptual decisions--in a unified manner.

Overall gloss evaluation in the presence of multiple cues to surface glossiness.

PubMed

Leloup, Frédéric B; Pointer, Michael R; Dutré, Philip; Hanselaer, Peter

2012-06-01

Human observers use the information offered by various visual cues when evaluating the glossiness of a surface. Several studies have demonstrated the effect of each single cue to glossiness, but little has been reported on how multiple cues are integrated for the perception of surface gloss. This paper reports on a psychophysical study with real stimuli that are different regarding multiple visual gloss criteria. Four samples were presented to 15 observers under different conditions of illumination in a light booth, resulting in a series of 16 stimuli. Through pairwise comparisons, an overall gloss scale was derived, from which it could be concluded that both differences in the distinctness of the reflected image and differences in luminance affect gloss perception. However, an investigation of the observers' strategy to evaluate gloss indicated a dichotomy among observers. One group of observers used the distinctness-of-image as a principal cue to glossiness, while the second group evaluated gloss primarily from differences in luminance of both the specular highlight and the diffuse background. It could therefore be questioned whether surface gloss can be characterized with one single quantity, or that a set of quantities is necessary to describe the gloss differences between objects.

Integration of polarization and chromatic cues in the insect sky compass.

PubMed

el Jundi, Basil; Pfeiffer, Keram; Heinze, Stanley; Homberg, Uwe

2014-06-01

Animals relying on a celestial compass for spatial orientation may use the position of the sun, the chromatic or intensity gradient of the sky, the polarization pattern of the sky, or a combination of these cues as compass signals. Behavioral experiments in bees and ants, indeed, showed that direct sunlight and sky polarization play a role in sky compass orientation, but the relative importance of these cues are species-specific. Intracellular recordings from polarization-sensitive interneurons in the desert locust and monarch butterfly suggest that inputs from different eye regions, including polarized-light input through the dorsal rim area of the eye and chromatic/intensity gradient input from the main eye, are combined at the level of the medulla to create a robust compass signal. Conflicting input from the polarization and chromatic/intensity channel, resulting from eccentric receptive fields, is eliminated at the level of the anterior optic tubercle and central complex through internal compensation for changing solar elevations, which requires input from a circadian clock. Across several species, the central complex likely serves as an internal sky compass, combining E-vector information with other celestial cues. Descending neurons, likewise, respond both to zenithal polarization and to unpolarized cues in an azimuth-dependent way.

When irrelevance matters: Stimulus-response binding in decision making under uncertainty.

PubMed

Nett, Nadine; Bröder, Arndt; Frings, Christian

2015-11-01

According to distractor-based response retrieval (Frings, Rothermund, & Wentura, 2007), irrelevant information will be integrated with the response to the relevant stimuli and further, the immediate repetition of irrelevant information can retrieve the previously executed response thereby influencing responding to the current target (leading either to benefits or costs if the retrieved response is compatible or incompatible, respectively, to the currently demanded response). We analyzed whether this effect also holds for decisions rather than simple motoric reactions. The hypothesis was tested in 4 experiments in which participants had to decide as fast as possible which disease an imagined patient suffered from. The decisions were based on 2 cues; 1 did not give any hint for a disease (the irrelevant cue), whereas the other did (the relevant cue). We found a significant influence of repeating the irrelevant cue on decision behavior. That is, participants tended to repeat their decision if the irrelevant cue was repeated in the following decision situation. Thus, stimulus-response binding which typically is discussed in basic processes of perception and action has also implications for arguably more deliberative cognitive processes in decision making under uncertainty. (c) 2015 APA, all rights reserved).

Perhaps More Consideration of Pavlovian–Operant Interaction May Improve the Clinical Efficacy of Behaviorally Based Drug Treatment Programs

PubMed Central

Troisi, Joseph R.

2014-01-01

Drug abuse remains costly. Drug-related cues can evoke cue-reactivity and craving, contributing to relapse. The Pavlovian extinction-based cue-exposure therapy (CET) has not been very successful in treating drug abuse. A functional operant analysis of complex rituals involved in CET is outlined and reinterpreted as an operant heterogeneous chain maintained by observing responses, conditioned reinforcers, and discriminative stimuli. It is further noted that operant functions are not predicated on Pavlovian processes but can be influenced by them in contributing to relapse; several empirical studies from the animal and human literature highlight this view. Cue-reactivity evoked by Pavlovian processes is conceptualized as an operant establishing/motivating operation. CET may be more effective in incorporating an operant-based approach that takes into account the complexity of Pavlovian–operant interaction. Extinction of the operant chain coupled with the shaping of alternative behaviors is proposed as an integrated therapy. It is proposed that operant-based drug abuse treatments (contingency management, voucher programs, and the therapeutic work environment) might consider incorporating cue-reactivity, as establishing/motivating operations, to increase long-term success—a hybrid approach based on Pavlovian–operant interaction. PMID:25346551

Perhaps More Consideration of Pavlovian-Operant Interaction May Improve the Clinical Efficacy of Behaviorally Based Drug Treatment Programs.

PubMed

Troisi, Joseph R

2013-01-01

Drug abuse remains costly. Drug-related cues can evoke cue-reactivity and craving, contributing to relapse. The Pavlovian extinction-based cue-exposure therapy (CET) has not been very successful in treating drug abuse. A functional operant analysis of complex rituals involved in CET is outlined and reinterpreted as an operant heterogeneous chain maintained by observing responses, conditioned reinforcers, and discriminative stimuli. It is further noted that operant functions are not predicated on Pavlovian processes but can be influenced by them in contributing to relapse; several empirical studies from the animal and human literature highlight this view. Cue-reactivity evoked by Pavlovian processes is conceptualized as an operant establishing/motivating operation. CET may be more effective in incorporating an operant-based approach that takes into account the complexity of Pavlovian-operant interaction. Extinction of the operant chain coupled with the shaping of alternative behaviors is proposed as an integrated therapy. It is proposed that operant-based drug abuse treatments (contingency management, voucher programs, and the therapeutic work environment) might consider incorporating cue-reactivity, as establishing/motivating operations, to increase long-term success-a hybrid approach based on Pavlovian-operant interaction.

Integrating advice and experience: learning and decision making with social and nonsocial cues.

PubMed

Collins, Elizabeth C; Percy, Elise J; Smith, Eliot R; Kruschke, John K

2011-06-01

When making decisions, people typically gather information from both social and nonsocial sources, such as advice from others and direct experience. This research adapted a cognitive learning paradigm to examine the process by which people learn what sources of information are credible. When participants relied on advice alone to make decisions, their learning of source reliability proceeded in a manner analogous to traditional cue learning processes and replicated the established learning phenomena. However, when advice and nonsocial cues were encountered together as an established phenomenon, blocking (ignoring redundant information) did not occur. Our results suggest that extant cognitive learning models can accommodate either advice or nonsocial cues in isolation. However, the combination of advice and nonsocial cues (a context more typically encountered in daily life) leads to different patterns of learning, in which mutually supportive information from different types of sources is not regarded as redundant and may be particularly compelling. For these situations, cognitive learning models still constitute a promising explanatory tool but one that must be expanded. As such, these findings have important implications for social psychological theory and for cognitive models of learning. 2011 APA, all rights reserved

Avian brood parasitism: information use and variation in egg-rejection behavior.

PubMed

Svennungsen, Thomas Owens; Holen, Øistein Haugsten

2010-05-01

Hosts of avian brood parasites often vary in their response to parasitized clutches: they may eject one or several eggs, desert the nest, or accept all the eggs. Focusing on hosts exposed to single-egg parasitism by an evicting brood parasite, we construct an optimality model that includes all these behavioral options and use it to explore variation in rejection behavior. We particularly consider the influence of egg mimicry and external cues (observations of adult parasites near the nest) on optimal choice of rejection behavior. We find that several rejection responses will be present in a host population under a wide range of conditions. Ejection of multiple eggs tends to be adaptive when egg mimicry is fairly accurate, external cues provide reliable information of the risk of parasitism, and the expected success of renesting is low. If the perceived risk of parasitism is high, ejection of one or a few eggs may be the optimal rejection response even in cases in which hosts cannot discriminate between eggs. This may have consequences for the long-term outcome of the coevolutionary chase between hosts and parasites. We propose an alternative evolutionary pathway by which egg ejection may first arise as a defense against brood parasitism.

A psychophysical investigation of differences between synchrony and temporal order judgments.

PubMed

Love, Scott A; Petrini, Karin; Cheng, Adam; Pollick, Frank E

2013-01-01

Synchrony judgments involve deciding whether cues to an event are in synch or out of synch, while temporal order judgments involve deciding which of the cues came first. When the cues come from different sensory modalities these judgments can be used to investigate multisensory integration in the temporal domain. However, evidence indicates that that these two tasks should not be used interchangeably as it is unlikely that they measure the same perceptual mechanism. The current experiment further explores this issue across a variety of different audiovisual stimulus types. Participants were presented with 5 audiovisual stimulus types, each at 11 parametrically manipulated levels of cue asynchrony. During separate blocks, participants had to make synchrony judgments or temporal order judgments. For some stimulus types many participants were unable to successfully make temporal order judgments, but they were able to make synchrony judgments. The mean points of subjective simultaneity for synchrony judgments were all video-leading, while those for temporal order judgments were all audio-leading. In the within participants analyses no correlation was found across the two tasks for either the point of subjective simultaneity or the temporal integration window. Stimulus type influenced how the two tasks differed; nevertheless, consistent differences were found between the two tasks regardless of stimulus type. Therefore, in line with previous work, we conclude that synchrony and temporal order judgments are supported by different perceptual mechanisms and should not be interpreted as being representative of the same perceptual process.

A Psychophysical Investigation of Differences between Synchrony and Temporal Order Judgments

PubMed Central

Love, Scott A.; Petrini, Karin; Cheng, Adam; Pollick, Frank E.

2013-01-01

Background Synchrony judgments involve deciding whether cues to an event are in synch or out of synch, while temporal order judgments involve deciding which of the cues came first. When the cues come from different sensory modalities these judgments can be used to investigate multisensory integration in the temporal domain. However, evidence indicates that that these two tasks should not be used interchangeably as it is unlikely that they measure the same perceptual mechanism. The current experiment further explores this issue across a variety of different audiovisual stimulus types. Methodology/Principal Findings Participants were presented with 5 audiovisual stimulus types, each at 11 parametrically manipulated levels of cue asynchrony. During separate blocks, participants had to make synchrony judgments or temporal order judgments. For some stimulus types many participants were unable to successfully make temporal order judgments, but they were able to make synchrony judgments. The mean points of subjective simultaneity for synchrony judgments were all video-leading, while those for temporal order judgments were all audio-leading. In the within participants analyses no correlation was found across the two tasks for either the point of subjective simultaneity or the temporal integration window. Conclusions Stimulus type influenced how the two tasks differed; nevertheless, consistent differences were found between the two tasks regardless of stimulus type. Therefore, in line with previous work, we conclude that synchrony and temporal order judgments are supported by different perceptual mechanisms and should not be interpreted as being representative of the same perceptual process. PMID:23349971

Social dominance modulates eavesdropping in zebrafish

PubMed Central

Abril-de-Abreu, Rodrigo; Cruz, Ana S.; Oliveira, Rui F.

2015-01-01

Group living animals may eavesdrop on signalling interactions between conspecifics and integrate it with their own past social experience in order to optimize the use of relevant information from others. However, little is known about this interplay between public (eavesdropped) and private social information. To investigate it, we first manipulated the dominance status of bystander zebrafish. Next, we either allowed or prevented bystanders from observing a fight. Finally, we assessed their behaviour towards the winners and losers of the interaction, using a custom-made video-tracking system and directional analysis. We found that only dominant bystanders who had seen the fight revealed a significant increase in directional focus (a measure of attention) towards the losers of the fights. Furthermore, our results indicate that information about the fighters' acquired status was collected from the signalling interaction itself and not from post-interaction status cues, which implies the existence of individual recognition in zebrafish. Thus, we show for the first time that zebrafish, a highly social model organism, eavesdrop on conspecific agonistic interactions and that this process is modulated by the eavesdroppers' dominance status. We suggest that this type of integration of public and private information may be ubiquitous in social learning processes. PMID:26361550

Neural basis of the cognitive map: path integration does not require hippocampus or entorhinal cortex.

PubMed

Shrager, Yael; Kirwan, C Brock; Squire, Larry R

2008-08-19

The hippocampus and entorhinal cortex have been linked to both memory functions and to spatial cognition, but it has been unclear how these ideas relate to each other. An important part of spatial cognition is the ability to keep track of a reference location using self-motion cues (sometimes referred to as path integration), and it has been suggested that the hippocampus or entorhinal cortex is essential for this ability. Patients with hippocampal lesions or larger lesions that also included entorhinal cortex were led on paths while blindfolded (up to 15 m in length) and were asked to actively maintain the path in mind. Patients pointed to and estimated their distance from the start location as accurately as controls. A rotation condition confirmed that performance was based on self-motion cues. When demands on long-term memory were increased, patients were impaired. Thus, in humans, the hippocampus and entorhinal cortex are not essential for path integration.

Effects of varenicline and cognitive bias modification on neural response to smoking-related cues: study protocol for a randomized controlled study.

PubMed

Attwood, Angela S; Williams, Tim; Adams, Sally; McClernon, Francis J; Munafò, Marcus R

2014-10-07

Smoking-related cues can trigger drug-seeking behaviors, and computer-based interventions that reduce cognitive biases towards such cues may be efficacious and cost-effective cessation aids. In order to optimize such interventions, there needs to be better understanding of the mechanisms underlying the effects of cognitive bias modification (CBM). Here we present a protocol for an investigation of the neural effects of CBM and varenicline in non-quitting daily smokers. We will recruit 72 daily smokers who report smoking at least 10 manufactured cigarettes or 15 roll-ups per day and who smoke within one hour of waking. Participants will attend two sessions approximately one week apart. At the first session participants will be screened for eligibility and randomized to receive either varenicline or a placebo over a seven-day period. On the final drug-taking day (day seven) participants will attend a second session and be further randomized to one of three CBM conditions (training towards smoking cues, training away from smoking cues, or control training). Participants will then undergo a functional magnetic resonance imaging scan during which they will view smoking-related pictorial cues. Primary outcome measures are changes in cognitive bias as measured by the visual dot-probe task, and neural responses to smoking-related cues. Secondary outcome measures will be cognitive bias as measured by a transfer task (modified Stroop test of smoking-related cognitive bias) and subjective mood and cigarette craving. This study will add to the relatively small literature examining the effects of CBM in addictions. It will address novel questions regarding the neural effects of CBM. It will also investigate whether varenicline treatment alters neural response to smoking-related cues. These findings will inform future research that can develop behavioral treatments that target relapse prevention. Registered with Current Controlled Trials: ISRCTN65690030. Registered on 30 January 2014.

Missing depth cues in virtual reality limit performance and quality of three dimensional reaching movements

PubMed Central

Mayo, Johnathan; Baur, Kilian; Wittmann, Frieder; Riener, Robert; Wolf, Peter

2018-01-01

Background Goal-directed reaching for real-world objects by humans is enabled through visual depth cues. In virtual environments, the number and quality of available visual depth cues is limited, which may affect reaching performance and quality of reaching movements. Methods We assessed three-dimensional reaching movements in five experimental groups each with ten healthy volunteers. Three groups used a two-dimensional computer screen and two groups used a head-mounted display. The first screen group received the typically recreated visual depth cues, such as aerial and linear perspective, occlusion, shadows, and texture gradients. The second screen group received an abstract minimal rendering lacking those. The third screen group received the cues of the first screen group and absolute depth cues enabled by retinal image size of a known object, which realized with visual renderings of the handheld device and a ghost handheld at the target location. The two head-mounted display groups received the same virtually recreated visual depth cues as the second or the third screen group respectively. Additionally, they could rely on stereopsis and motion parallax due to head-movements. Results and conclusion All groups using the screen performed significantly worse than both groups using the head-mounted display in terms of completion time normalized by the straight-line distance to the target. Both groups using the head-mounted display achieved the optimal minimum in number of speed peaks and in hand path ratio, indicating that our subjects performed natural movements when using a head-mounted display. Virtually recreated visual depth cues had a minor impact on reaching performance. Only the screen group with rendered handhelds could outperform the other screen groups. Thus, if reaching performance in virtual environments is in the main scope of a study, we suggest applying a head-mounted display. Otherwise, when two-dimensional screens are used, achievable performance is likely limited by the reduced depth perception and not just by subjects’ motor skills. PMID:29293512

Endogenous-cue prospective memory involving incremental updating of working memory: an fMRI study.

PubMed

Halahalli, Harsha N; John, John P; Lukose, Ammu; Jain, Sanjeev; Kutty, Bindu M

2015-11-01

Prospective memory paradigms are conventionally classified on the basis of event-, time-, or activity-based intention retrieval. In the vast majority of such paradigms, intention retrieval is provoked by some kind of external event. However, prospective memory retrieval cues that prompt intention retrieval in everyday life are commonly endogenous, i.e., linked to a specific imagined retrieval context. We describe herein a novel prospective memory paradigm wherein the endogenous cue is generated by incremental updating of working memory, and investigated the hemodynamic correlates of this task. Eighteen healthy adult volunteers underwent functional magnetic resonance imaging while they performed a prospective memory task where the delayed intention was triggered by an endogenous cue generated by incremental updating of working memory. Working memory and ongoing task control conditions were also administered. The 'endogenous-cue prospective memory condition' with incremental working memory updating was associated with maximum activations in the right rostral prefrontal cortex, and additional activations in the brain regions that constitute the bilateral fronto-parietal network, central and dorsal salience networks as well as cerebellum. In the working memory control condition, maximal activations were noted in the left dorsal anterior insula. Activation of the bilateral dorsal anterior insula, a component of the central salience network, was found to be unique to this 'endogenous-cue prospective memory task' in comparison to previously reported exogenous- and endogenous-cue prospective memory tasks without incremental working memory updating. Thus, the findings of the present study highlight the important role played by the dorsal anterior insula in incremental working memory updating that is integral to our endogenous-cue prospective memory task.

Dissociable corticostriatal circuits underlie goal-directed vs. cue-elicited habitual food seeking after satiation: evidence from a multimodal MRI study.

PubMed

van Steenbergen, Henk; Watson, Poppy; Wiers, Reinout W; Hommel, Bernhard; de Wit, Sanne

2017-07-01

The present multimodal MRI study advances our understanding of the corticostriatal circuits underlying goal-directed vs. cue-driven, habitual food seeking. To this end, we employed a computerized Pavlovian-instrumental transfer paradigm. During the test phase, participants were free to perform learned instrumental responses (left and right key presses) for popcorn and Smarties outcomes. Importantly, prior to this test half of the participants had been sated on popcorn and the other half on Smarties - resulting in a reduced desirability of those outcomes. Furthermore, during a proportion of the test trials, food-associated Pavlovian cues were presented in the background. In line with previous studies, we found that participants were able to perform in a goal-directed manner in the absence of Pavlovian cues, meaning that specific satiation selectively reduced responding for that food. However, presentation of Pavlovian cues biased choice toward the associated food reward regardless of satiation. Functional MRI analyses revealed that, in the absence of Pavlovian cues, posterior ventromedial prefrontal cortex tracked outcome value. In contrast, during cued trials, the BOLD signal in the posterior putamen differentiated between responses compatible and incompatible with the cue-associated outcome. Furthermore, we identified a region in ventral amygdala showing relatively strong functional connectivity with posterior putamen during the cued trials. Structural MRI analyses provided converging evidence for the involvement of corticostriatal circuits: diffusion tensor imaging data revealed that connectivity of caudate-seeded white-matter tracts to the ventromedial prefrontal cortex predicted responding for still-valuable outcomes; and gray matter integrity in the premotor cortex predicted individual Pavlovian cueing effects. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

A Neural Computational Model of Incentive Salience

PubMed Central

Zhang, Jun; Berridge, Kent C.; Tindell, Amy J.; Smith, Kyle S.; Aldridge, J. Wayne

2009-01-01

Incentive salience is a motivational property with ‘magnet-like’ qualities. When attributed to reward-predicting stimuli (cues), incentive salience triggers a pulse of ‘wanting’ and an individual is pulled toward the cues and reward. A key computational question is how incentive salience is generated during a cue re-encounter, which combines both learning and the state of limbic brain mechanisms. Learning processes, such as temporal-difference models, provide one way for stimuli to acquire cached predictive values of rewards. However, empirical data show that subsequent incentive values are also modulated on the fly by dynamic fluctuation in physiological states, altering cached values in ways requiring additional motivation mechanisms. Dynamic modulation of incentive salience for a Pavlovian conditioned stimulus (CS or cue) occurs during certain states, without necessarily requiring (re)learning about the cue. In some cases, dynamic modulation of cue value occurs during states that are quite novel, never having been experienced before, and even prior to experience of the associated unconditioned reward in the new state. Such cases can include novel drug-induced mesolimbic activation and addictive incentive-sensitization, as well as natural appetite states such as salt appetite. Dynamic enhancement specifically raises the incentive salience of an appropriate CS, without necessarily changing that of other CSs. Here we suggest a new computational model that modulates incentive salience by integrating changing physiological states with prior learning. We support the model with behavioral and neurobiological data from empirical tests that demonstrate dynamic elevations in cue-triggered motivation (involving natural salt appetite, and drug-induced intoxication and sensitization). Our data call for a dynamic model of incentive salience, such as presented here. Computational models can adequately capture fluctuations in cue-triggered ‘wanting’ only by incorporating modulation of previously learned values by natural appetite and addiction-related states. PMID:19609350

Toddlers Default to Canonical Surface-to-Meaning Mapping When Learning Verbs

PubMed Central

Dautriche, Isabelle; Cristia, Alejandrina; Brusini, Perrine; Yuan, Sylvia; Fisher, Cynthia; Christophe, Anne

2013-01-01

Previous work has shown that toddlers readily encode each noun in the sentence as a distinct argument of the verb. However, languages allow multiple mappings between form and meaning which do not fit this canonical format. Two experiments examined French 28-month-olds’ interpretation of right-dislocated sentences (nouni-verb, nouni) where the presence of clear, language-specific cues should block such a canonical mapping. Toddlers (N = 96) interpreted novel verbs embedded in these sentences as transitive, disregarding prosodic cues to dislocation (Experiment 1) but correctly interpreted right-dislocated sentences containing well-known verbs (Experiment 2). These results suggest that toddlers can integrate multiple cues in ideal conditions, but default to canonical surface-to-meaning mapping when extracting structural information about novel verbs in semantically impoverished conditions. PMID:24117408

Central and peripheral vision loss differentially affects contextual cueing in visual search.

PubMed

Geringswald, Franziska; Pollmann, Stefan

2015-09-01

Visual search for targets in repeated displays is more efficient than search for the same targets in random distractor layouts. Previous work has shown that this contextual cueing is severely impaired under central vision loss. Here, we investigated whether central vision loss, simulated with gaze-contingent displays, prevents the incidental learning of contextual cues or the expression of learning, that is, the guidance of search by learned target-distractor configurations. Visual search with a central scotoma reduced contextual cueing both with respect to search times and gaze parameters. However, when the scotoma was subsequently removed, contextual cueing was observed in a comparable magnitude as for controls who had searched without scotoma simulation throughout the experiment. This indicated that search with a central scotoma did not prevent incidental context learning, but interfered with search guidance by learned contexts. We discuss the role of visuospatial working memory load as source of this interference. In contrast to central vision loss, peripheral vision loss was expected to prevent spatial configuration learning itself, because the restricted search window did not allow the integration of invariant local configurations with the global display layout. This expectation was confirmed in that visual search with a simulated peripheral scotoma eliminated contextual cueing not only in the initial learning phase with scotoma, but also in the subsequent test phase without scotoma. (c) 2015 APA, all rights reserved).

Computational Precision of Mental Inference as Critical Source of Human Choice Suboptimality.

PubMed

Drugowitsch, Jan; Wyart, Valentin; Devauchelle, Anne-Dominique; Koechlin, Etienne

2016-12-21

Making decisions in uncertain environments often requires combining multiple pieces of ambiguous information from external cues. In such conditions, human choices resemble optimal Bayesian inference, but typically show a large suboptimal variability whose origin remains poorly understood. In particular, this choice suboptimality might arise from imperfections in mental inference rather than in peripheral stages, such as sensory processing and response selection. Here, we dissociate these three sources of suboptimality in human choices based on combining multiple ambiguous cues. Using a novel quantitative approach for identifying the origin and structure of choice variability, we show that imperfections in inference alone cause a dominant fraction of suboptimal choices. Furthermore, two-thirds of this suboptimality appear to derive from the limited precision of neural computations implementing inference rather than from systematic deviations from Bayes-optimal inference. These findings set an upper bound on the accuracy and ultimate predictability of human choices in uncertain environments. Copyright © 2016 Elsevier Inc. All rights reserved.

Integration of visual and motion cues for simulator requirements and ride quality investigation. [computerized simulation of aircraft landing, visual perception of aircraft pilots

NASA Technical Reports Server (NTRS)

Young, L. R.

1975-01-01

Preliminary tests and evaluation are presented of pilot performance during landing (flight paths) using computer generated images (video tapes). Psychophysiological factors affecting pilot visual perception were measured. A turning flight maneuver (pitch and roll) was specifically studied using a training device, and the scaling laws involved were determined. Also presented are medical studies (abstracts) on human response to gravity variations without visual cues, acceleration stimuli effects on the semicircular canals, and neurons affecting eye movements, and vestibular tests.

Teasing apart the anticipatory and consummatory processing of monetary incentives: An event-related potential study of reward dynamics.

PubMed

Novak, Keisha D; Foti, Dan

2015-11-01

The monetary incentive delay (MID) task has been widely used in fMRI studies to investigate the neural networks involved in anticipatory and consummatory reward processing. Previous efforts to adapt the MID task for use with ERPs, however, have had limited success. Here, we sought to further decompose reward dynamics using a comprehensive set of anticipatory (cue-N2, cue-P3, contingent negative variation [CNV]) and consummatory ERPs (feedback negativity [FN], feedback P3 [fb-P3]). ERP data was recorded during adapted versions of the MID task across two experiments. Unlike previous studies, monetary incentive cues modulated the cue-N2, cue-P3, and CNV; however, cue-related ERPs and the CNV were uncorrelated with one another, indicating distinct anticipatory subprocesses. With regard to consummatory processing, FN amplitude primarily tracked outcome valence (reward vs. nonreward), whereas fb-P3 amplitude primarily tracked outcome salience (uncertain vs. certain). Independent modulation of the cue-P3 and fb-P3 was observed, indicating that these two P3 responses may uniquely capture the allocation of attention during anticipatory and consummatory reward processing, respectively. Overall, across two samples, consistent evidence of both anticipatory and consummatory ERP activity was observed on an adapted version of the MID paradigm, demonstrating for the first time how these ERP components may be integrated with one another to more fully characterize the time course of reward processing. This ERP-MID paradigm is well suited to parsing reward dynamics, and can be applied to both healthy and clinical populations. © 2015 Society for Psychophysiological Research.

Acoustic cue integration in speech intonation recognition with cochlear implants.

PubMed

Peng, Shu-Chen; Chatterjee, Monita; Lu, Nelson

2012-06-01

The present article reports on the perceptual weighting of prosodic cues in question-statement identification by adult cochlear implant (CI) listeners. Acoustic analyses of normal-hearing (NH) listeners' production of sentences spoken as questions or statements confirmed that in English the last bisyllabic word in a sentence carries the dominant cues (F0, duration, and intensity patterns) for the contrast. Furthermore, these analyses showed that the F0 contour is the primary cue for the question-statement contrast, with intensity and duration changes conveying important but less reliable information. On the basis of these acoustic findings, the authors examined adult CI listeners' performance in two question-statement identification tasks. In Task 1, 13 CI listeners' question-statement identification accuracy was measured using naturally uttered sentences matched for their syntactic structures. In Task 2, the same listeners' perceptual cue weighting in question-statement identification was assessed using resynthesized single-word stimuli, within which fundamental frequency (F0), intensity, and duration properties were systematically manipulated. Both tasks were also conducted with four NH listeners with full-spectrum and noise-band-vocoded stimuli. Perceptual cue weighting was assessed by comparing the estimated coefficients in logistic models fitted to the data. Of the 13 CI listeners, 7 achieved high performance levels in Task 1. The results of Task 2 indicated that multiple sources of acoustic cues for question-statement identification were utilized to different extents depending on the listening conditions (e.g., full spectrum vs. spectrally degraded) or the listeners' hearing and amplification status (e.g., CI vs. NH).

Differences in the reliance on cuticular hydrocarbons as sexual signaling and species discrimination cues in parasitoid wasps.

PubMed

Buellesbach, Jan; Vetter, Sebastian G; Schmitt, Thomas

2018-01-01

Cuticular hydrocarbons (CHC) have been documented to play crucial roles as species- and sex-specific cues in the chemical communication systems of a wide variety of insects. However, whether they are sufficient by themselves as the sole cue triggering sexual behavior as well as preference of con- over heterospecific mating partners is rarely assessed. We conducted behavioral assays in three representative species of parasitoid wasps (Hymenoptera: Pteromalidae) to determine their reliance on CHC as species-specific sexual signaling cues. We found a surprising degree of either unspecific or insufficient sexual signaling when CHC are singled out as recognition cues. Most strikingly, the cosmopolitan species Nasonia vitripennis , expected to experience enhanced selection pressure to discriminate against other co-occurring parasitoids, did not discriminate against CHC of a partially sympatric species from another genus, Trichomalopsis sarcophagae . Focusing on the latter species, in turn, it became apparent that CHC are even insufficient as the sole cue triggering conspecific sexual behavior, hinting at the requirement of additional, synergistic sexual cues particularly important in this species. Finally, in the phylogenetically and chemically most divergent species Muscidifurax uniraptor, we intriguingly found both CHC-based sexual signaling as well as species discrimination behavior intact although this species is naturally parthenogenetic with sexual reproduction only occurring under laboratory conditions. Our findings implicate a discrepancy in the reliance on and specificity of CHC as sexual cues in our tested parasitioid wasps. CHC profiles were not sufficient for unambiguous discrimination and preference behavior, as demonstrated by clear cross-attraction between some of our tested wasp genera. Moreover, we could show that only in T. sarcophagae , additional behavioral cues need to be present for triggering natural mating behavior, hinting at an interesting shift in signaling hierarchy in this particular species. This demonstrates the importance of integrating multiple, potentially complementary signaling modalities in future studies for a better understanding of their individual contributions to natural sexual communication behavior.

What Do the Numbers Say? Clarifying Our Interpretation of Carbon Use Efficiency Data from Soil.

NASA Astrophysics Data System (ADS)

Geyer, K.; Dijkstra, P.; Sinsabaugh, R. L.; Frey, S. D.

2017-12-01

Carbon use efficiency (CUE) is the proportion of carbon resources that a microorganism commits towards cellular growth and thus affects the dynamics of soil organic matter pools. While numerous approaches exist for estimating CUE, no attempts have been made to simultaneously compare methods and reconcile their inherent biases. Such work is necessary to partition the observed variation in CUE estimates (commonly between 0.3 - 0.7) as biological or technical in origin. Here we review our results from experimental work aimed at comparing both traditional and emerging CUE techniques. Soil from the Harvard Forest Long Term Ecological Research site in Massachusetts, USA, was amended with 13C-glucose and 18O-water in laboratory mesocosms and monitored for changing rates of soil dissolved organic carbon (DOC) uptake, respiration (R), microbial biomass (MBC) production, DNA synthesis, and heat (Q) flux over 72 hrs. Three CUE estimates were generated from this data: 1) Δ13MBC/(Δ13MBC+ 13R), 2) Δ18DNA/(Δ18DNA + R), 3) Q/R. CUE was also measured via two indirect techniques: metabolic flux modeling and stoichiometric modeling. Results indicate that the 18O technique is able to discern gross growth of soil microbes while the 13C technique indicates net growth. As a result, 18O-based CUE remains unchanged ( 0.45) for the incubation duration at low amendment rates (0.0 and 0.05 mg glucose-C/g) while 13C-based CUE declines with time (0.75 to 0.5). The 13C technique likely overestimates CUE because the numerator (Δ13MBC) integrates any label (whether or not destined for growth) residing within the cell. High amendment rates (2.0 mg glucose-C/g) cause dramatic declines in 18O- and 13C-based CUE for the first 24 hr of incubation, but neither modeling approach was able to detect these dynamics. In summary, our results suggest that 13C-based estimates of CUE are best interpreted as net changes in the residence of labeled substrate within MBC pools while 18O-based estimates directly capture gross growth dynamics. Metabolic flux modeling and stoichiometric modeling appear to be suited for conditions of steady-state MBC only, where they approximate the CUE magnitude of the 13C- and 18O-based approaches, respectively.

The answer is blowing in the wind: free-flying honeybees can integrate visual and mechano-sensory inputs for making complex foraging decisions.

PubMed

Ravi, Sridhar; Garcia, Jair E; Wang, Chun; Dyer, Adrian G

2016-11-01

Bees navigate in complex environments using visual, olfactory and mechano-sensorial cues. In the lowest region of the atmosphere, the wind environment can be highly unsteady and bees employ fine motor-skills to enhance flight control. Recent work reveals sophisticated multi-modal processing of visual and olfactory channels by the bee brain to enhance foraging efficiency, but it currently remains unclear whether wind-induced mechano-sensory inputs are also integrated with visual information to facilitate decision making. Individual honeybees were trained in a linear flight arena with appetitive-aversive differential conditioning to use a context-setting cue of 3 m s -1 cross-wind direction to enable decisions about either a 'blue' or 'yellow' star stimulus being the correct alternative. Colour stimuli properties were mapped in bee-specific opponent-colour spaces to validate saliency, and to thus enable rapid reverse learning. Bees were able to integrate mechano-sensory and visual information to facilitate decisions that were significantly different to chance expectation after 35 learning trials. An independent group of bees were trained to find a single rewarding colour that was unrelated to the wind direction. In these trials, wind was not used as a context-setting cue and served only as a potential distracter in identifying the relevant rewarding visual stimuli. Comparison between respective groups shows that bees can learn to integrate visual and mechano-sensory information in a non-elemental fashion, revealing an unsuspected level of sensory processing in honeybees, and adding to the growing body of knowledge on the capacity of insect brains to use multi-modal sensory inputs in mediating foraging behaviour. © 2016. Published by The Company of Biologists Ltd.

Integration of visual and non-visual self-motion cues during voluntary head movements in the human brain.

PubMed

Schindler, Andreas; Bartels, Andreas

2018-05-15

Our phenomenological experience of the stable world is maintained by continuous integration of visual self-motion with extra-retinal signals. However, due to conventional constraints of fMRI acquisition in humans, neural responses to visuo-vestibular integration have only been studied using artificial stimuli, in the absence of voluntary head-motion. We here circumvented these limitations and let participants to move their heads during scanning. The slow dynamics of the BOLD signal allowed us to acquire neural signal related to head motion after the observer's head was stabilized by inflatable aircushions. Visual stimuli were presented on head-fixed display goggles and updated in real time as a function of head-motion that was tracked using an external camera. Two conditions simulated forward translation of the participant. During physical head rotation, the congruent condition simulated a stable world, whereas the incongruent condition added arbitrary lateral motion. Importantly, both conditions were precisely matched in visual properties and head-rotation. By comparing congruent with incongruent conditions we found evidence consistent with the multi-modal integration of visual cues with head motion into a coherent "stable world" percept in the parietal operculum and in an anterior part of parieto-insular cortex (aPIC). In the visual motion network, human regions MST, a dorsal part of VIP, the cingulate sulcus visual area (CSv) and a region in precuneus (Pc) showed differential responses to the same contrast. The results demonstrate for the first time neural multimodal interactions between precisely matched congruent versus incongruent visual and non-visual cues during physical head-movement in the human brain. The methodological approach opens the path to a new class of fMRI studies with unprecedented temporal and spatial control over visuo-vestibular stimulation. Copyright © 2018 Elsevier Inc. All rights reserved.

Calibration of magnetic and celestial compass cues in migratory birds--a review of cue-conflict experiments.

PubMed

Muheim, Rachel; Moore, Frank R; Phillips, John B

2006-01-01

Migratory birds use multiple sources of compass information for orientation, including the geomagnetic field, the sun, skylight polarization patterns and star patterns. In this paper we review the results of cue-conflict experiments designed to determine the relative importance of the different compass mechanisms, and how directional information from these compass mechanisms is integrated. We focus on cue-conflict experiments in which the magnetic field was shifted in alignment relative to natural celestial cues. Consistent with the conclusions of earlier authors, our analyses suggest that during the premigratory season, celestial information is given the greatest salience and used to recalibrate the magnetic compass by both juvenile and adult birds. Sunset polarized light patterns from the region of the sky near the horizon appear to provide the calibration reference for the magnetic compass. In contrast, during migration, a majority of experiments suggest that birds rely on the magnetic field as the primary source of compass information and use it to calibrate celestial compass cues, i.e. the relative saliency of magnetic and celestial cues is reversed. An alternative possibility, however, is suggested by several experiments in which birds exposed to a cue conflict during migration appear to have recalibrated the magnetic compass, i.e. their response is similar to that of birds exposed to cue conflicts during the premigratory season. The general pattern to emerge from these analyses is that birds exposed to the cue conflict with a view of the entire sunset sky tended to recalibrate the magnetic compass, regardless of whether the cue conflict occurred during the premigratory or migratory period. In contrast, birds exposed to the cue conflict in orientation funnels and registration cages that restricted their view of the region of sky near the horizon (as was generally the case in experiments carried out during the migratory season) did not recalibrate the magnetic compass but, instead, used the magnetic compass to calibrate the other celestial compass systems. If access to critical celestial cues, rather than the timing of exposure to the cue conflict (i.e. premigratory vs migratory), determines whether recalibration of the magnetic compass occurs, this suggests that under natural conditions there may be a single calibration reference for all of the compass systems of migratory birds that is derived from sunset (and possibly also sunrise) polarized light cues from the region of sky near the horizon. In cue-conflict experiments carried out during the migratory season, there was also an interesting asymmetry in the birds' response to magnetic fields shifted clockwise and counterclockwise relative to celestial cues. We discuss two possible explanations for these differences: (1) lateral asymmetry in the role of the right and left eye in mediating light-dependent magnetic compass orientation and (2) interference from the spectral and intensity distribution of skylight at sunset with the response of the light-dependent magnetic compass.

Temperature as a universal resetting cue for mammalian circadian oscillators

PubMed Central

Buhr, Ethan D.; Yoo, Seung-Hee; Takahashi, Joseph S.

2011-01-01

Environmental temperature cycles are a universal entraining cue for all circadian systems at the organismal level with the exception of homeothermic vertebrates. We report here that resistance to temperature entrainment is a property of the suprachiasmatic nucleus (SCN) network and is not a cell autonomous property of mammalian clocks. This differential sensitivity to temperature allows the SCN to drive circadian rhythms in body temperature which can then act as a universal cue for the entrainment of cell autonomous oscillators throughout the body. Pharmacological experiments show that network interactions in the SCN are required for temperature resistance and that the heat shock pathway is integral to temperature resetting and temperature compensation in mammalian cells. These results suggest that the evolutionarily ancient temperature resetting response can be utilized in homeothermic animals to enhance internal circadian synchronization. PMID:20947768

Temperature as a universal resetting cue for mammalian circadian oscillators.

PubMed

Buhr, Ethan D; Yoo, Seung-Hee; Takahashi, Joseph S

2010-10-15

Environmental temperature cycles are a universal entraining cue for all circadian systems at the organismal level with the exception of homeothermic vertebrates. We report here that resistance to temperature entrainment is a property of the suprachiasmatic nucleus (SCN) network and is not a cell-autonomous property of mammalian clocks. This differential sensitivity to temperature allows the SCN to drive circadian rhythms in body temperature, which can then act as a universal cue for the entrainment of cell-autonomous oscillators throughout the body. Pharmacological experiments show that network interactions in the SCN are required for temperature resistance and that the heat shock pathway is integral to temperature resetting and temperature compensation in mammalian cells. These results suggest that the evolutionarily ancient temperature resetting response can be used in homeothermic animals to enhance internal circadian synchronization.

Words are not enough: how preschoolers' integration of perspective and emotion informs their referential understanding.

PubMed

Graham, Susan A; San Juan, Valerie; Khu, Melanie

2017-05-01

When linguistic information alone does not clarify a speaker's intended meaning, skilled communicators can draw on a variety of cues to infer communicative intent. In this paper, we review research examining the developmental emergence of preschoolers' sensitivity to a communicative partner's perspective. We focus particularly on preschoolers' tendency to use cues both within the communicative context (i.e. a speaker's visual access to information) and within the speech signal itself (i.e. emotional prosody) to make on-line inferences about communicative intent. Our review demonstrates that preschoolers' ability to use visual and emotional cues of perspective to guide language interpretation is not uniform across tasks, is sometimes related to theory of mind and executive function skills, and, at certain points of development, is only revealed by implicit measures of language processing.

Effects of aging on audio-visual speech integration.

PubMed

Huyse, Aurélie; Leybaert, Jacqueline; Berthommier, Frédéric

2014-10-01

This study investigated the impact of aging on audio-visual speech integration. A syllable identification task was presented in auditory-only, visual-only, and audio-visual congruent and incongruent conditions. Visual cues were either degraded or unmodified. Stimuli were embedded in stationary noise alternating with modulated noise. Fifteen young adults and 15 older adults participated in this study. Results showed that older adults had preserved lipreading abilities when the visual input was clear but not when it was degraded. The impact of aging on audio-visual integration also depended on the quality of the visual cues. In the visual clear condition, the audio-visual gain was similar in both groups and analyses in the framework of the fuzzy-logical model of perception confirmed that older adults did not differ from younger adults in their audio-visual integration abilities. In the visual reduction condition, the audio-visual gain was reduced in the older group, but only when the noise was stationary, suggesting that older participants could compensate for the loss of lipreading abilities by using the auditory information available in the valleys of the noise. The fuzzy-logical model of perception confirmed the significant impact of aging on audio-visual integration by showing an increased weight of audition in the older group.

Eyes only? Perceiving eye contact is neither sufficient nor necessary for attentional capture by face direction.

PubMed

Böckler, Anne; van der Wel, Robrecht P R D; Welsh, Timothy N

2015-09-01

Direct eye contact and motion onset both constitute powerful cues that capture attention. Recent research suggests that (social) gaze and (non-social) motion onset influence information processing in parallel, even when combined as sudden onset direct gaze cues (i.e., faces suddenly establishing eye contact). The present study investigated the role of eye visibility for attention capture by these sudden onset face cues. To this end, face direction was manipulated (away or towards onlooker) while faces had closed eyes (eliminating visibility of eyes, Experiment 1), wore sunglasses (eliminating visible eyes, but allowing for the expectation of eyes to be open, Experiment 2), and were inverted with visible eyes (disrupting the integration of eyes and faces, Experiment 3). Participants classified targets appearing on one of four faces. Initially, two faces were oriented towards participants and two faces were oriented away from participants. Simultaneous to target presentation, one averted face became directed and one directed face became averted. Attention capture by face direction (i.e., facilitation for faces directed towards participants) was absent when eyes were closed, but present when faces wore sunglasses. Sudden onset direct faces can, hence, induce attentional capture, even when lacking eye cues. Inverted faces, by contrast, did not elicit attentional capture. Thus, when eyes cannot be integrated into a holistic face representation they are not sufficient to capture attention. Overall, the results suggest that visibility of eyes is neither necessary nor sufficient for the sudden direct face effect. Copyright © 2015 Elsevier B.V. All rights reserved.

A comparison of form processing involved in the perception of biological and nonbiological movements

PubMed Central

Thurman, Steven M.; Lu, Hongjing

2016-01-01

Although there is evidence for specialization in the human brain for processing biological motion per se, few studies have directly examined the specialization of form processing in biological motion perception. The current study was designed to systematically compare form processing in perception of biological (human walkers) to nonbiological (rotating squares) stimuli. Dynamic form-based stimuli were constructed with conflicting form cues (position and orientation), such that the objects were perceived to be moving ambiguously in two directions at once. In Experiment 1, we used the classification image technique to examine how local form cues are integrated across space and time in a bottom-up manner. By comparing with a Bayesian observer model that embodies generic principles of form analysis (e.g., template matching) and integrates form information according to cue reliability, we found that human observers employ domain-general processes to recognize both human actions and nonbiological object movements. Experiments 2 and 3 found differential top-down effects of spatial context on perception of biological and nonbiological forms. When a background does not involve social information, observers are biased to perceive foreground object movements in the direction opposite to surrounding motion. However, when a background involves social cues, such as a crowd of similar objects, perception is biased toward the same direction as the crowd for biological walking stimuli, but not for rotating nonbiological stimuli. The model provided an accurate account of top-down modulations by adjusting the prior probabilities associated with the internal templates, demonstrating the power and flexibility of the Bayesian approach for visual form perception. PMID:26746875

Learning dynamic control of body yaw orientation.

PubMed

Vimal, Vivekanand Pandey; Lackner, James R; DiZio, Paul

2018-05-01

To investigate the role of gravitational cues in the learning of a dynamic balancing task, we placed blindfolded subjects in a device programmed with inverted pendulum dynamics about the yaw axis. Subjects used a joystick to try and maintain a stable orientation at the direction of balance during 20 100 s-long trials. They pressed a trigger button on the joystick to indicate whenever they felt at the direction of balance. Three groups of ten subjects each participated. One group balanced with their body and the yaw axis vertical, and thus did not have gravitational cues to help them to determine their angular position. They showed minimal learning, inaccurate indications of the direction of balance, and a characteristic pattern of positional drifting away from the balance point. A second group balanced with the yaw axis pitched 45° from the gravitational vertical and had gravity relevant position cues. The third group balanced with their yaw axis horizontal where they had gravity-dependent cues about body position in yaw. Groups 2 and 3 showed better initial balancing performance and more learning across trials than Group 1. These results indicate that in the absence of vision, the integration of transient semicircular canal and somatosensory signals about angular acceleration is insufficient for determining angular position during dynamic balancing; direct position-dependent gravity cues are necessary.

Allothetic and idiothetic sensor fusion in rat-inspired robot localization

NASA Astrophysics Data System (ADS)

Weitzenfeld, Alfredo; Fellous, Jean-Marc; Barrera, Alejandra; Tejera, Gonzalo

2012-06-01

We describe a spatial cognition model based on the rat's brain neurophysiology as a basis for new robotic navigation architectures. The model integrates allothetic (external visual landmarks) and idiothetic (internal kinesthetic information) cues to train either rat or robot to learn a path enabling it to reach a goal from multiple starting positions. It stands in contrast to most robotic architectures based on SLAM, where a map of the environment is built to provide probabilistic localization information computed from robot odometry and landmark perception. Allothetic cues suffer in general from perceptual ambiguity when trying to distinguish between places with equivalent visual patterns, while idiothetic cues suffer from imprecise motions and limited memory recalls. We experiment with both types of cues in different maze configurations by training rats and robots to find the goal starting from a fixed location, and then testing them to reach the same target from new starting locations. We show that the robot, after having pre-explored a maze, can find a goal with improved efficiency, and is able to (1) learn the correct route to reach the goal, (2) recognize places already visited, and (3) exploit allothetic and idiothetic cues to improve on its performance. We finally contrast our biologically-inspired approach to more traditional robotic approaches and discuss current work in progress.

A Symposium: Relevant Cue Research, a Program of Systematic Evaluation: Considerations for Sustaining Instructional Design Research Using an Integrated Learning System.

ERIC Educational Resources Information Center

Grabowski, Barbara

An intelligent videodisc system on which comprehensive instructional development research can be conducted has been developed. This integrated learning system combines all other existing media, except objects, using a videodisc, microcomputer, printer, single monitor, hard disc storage with CPU for random access digitized audio, and headphones.…

Benefits of Accumulating versus Diminishing Cues in Recall

ERIC Educational Resources Information Center

Finley, Jason R.; Benjamin, Aaron S.; Hays, Matthew J.; Bjork, Robert A.; Kornell, Nate

2011-01-01

Optimizing learning over multiple retrieval opportunities requires a joint consideration of both the probability and the mnemonic value of a successful retrieval. Previous research has addressed this trade-off by manipulating the schedule of practice trials, suggesting that a pattern of increasingly long lags--"expanding retrieval practice"--may…

Ambient temperature response establishes ELF3 as a required component of the Arabidopsis core circadian clock

USDA-ARS?s Scientific Manuscript database

Circadian clocks synchronize internal processes with environmental cycles to ensure optimal timing of biological events on daily and seasonal timescales. External light and temperature cues set the core molecular oscillator to local conditions. In Arabidopsis, EARLY FLOWERING 3 (ELF3) is thought to ...

Bees without flowers: before peak bloom, diverse native bees find insect-produced honeydew sugars

USDA-ARS?s Scientific Manuscript database

Bee foragers respond to complex visual, olfactory, and extrasensory cues to optimize searches for floral rewards. Their abilities to detect and distinguish floral colors, shapes, volatiles, and ultraviolet signals, and even gauge nectar availability from changes in floral humidity or electric fields...

Phagostimulants for the Asian citrus psyllid also elicit volatile release from citrus leaves

USDA-ARS?s Scientific Manuscript database

Chemical cues that elicit orientation by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), are of great interest because it is the primary vector of the causal pathogen of citrus greening disease. We identified an optimal blend ratio of formic and acetic acids that stimulate...

Electrophysiology of prosodic and lexical-semantic processing during sentence comprehension in aphasia.

PubMed

Sheppard, Shannon M; Love, Tracy; Midgley, Katherine J; Holcomb, Phillip J; Shapiro, Lewis P

2017-12-01

Event-related potentials (ERPs) were used to examine how individuals with aphasia and a group of age-matched controls use prosody and themattic fit information in sentences containing temporary syntactic ambiguities. Two groups of individuals with aphasia were investigated; those demonstrating relatively good sentence comprehension whose primary language difficulty is anomia (Individuals with Anomic Aphasia (IWAA)), and those who demonstrate impaired sentence comprehension whose primary diagnosis is Broca's aphasia (Individuals with Broca's Aphasia (IWBA)). The stimuli had early closure syntactic structure and contained a temporary early closure (correct)/late closure (incorrect) syntactic ambiguity. The prosody was manipulated to either be congruent or incongruent, and the temporarily ambiguous NP was also manipulated to either be a plausible or an implausible continuation for the subordinate verb (e.g., "While the band played the song/the beer pleased all the customers."). It was hypothesized that an implausible NP in sentences with incongruent prosody may provide the parser with a plausibility cue that could be used to predict syntactic structure. The results revealed that incongruent prosody paired with a plausibility cue resulted in an N400-P600 complex at the implausible NP (the beer) in both the controls and the IWAAs, yet incongruent prosody without a plausibility cue resulted in an N400-P600 at the critical verb (pleased) only in healthy controls. IWBAs did not show evidence of N400 or P600 effects at the ambiguous NP or critical verb, although they did show evidence of a delayed N400 effect at the sentence-final word in sentences with incongruent prosody. These results suggest that IWAAs have difficulty integrating prosodic cues with underlying syntactic structure when lexical-semantic information is not available to aid their parse. IWBAs have difficulty integrating both prosodic and lexical-semantic cues with syntactic structure, likely due to a processing delay. Copyright © 2017 Elsevier Ltd. All rights reserved.

How is spatial context learning integrated over signal versus noise? A primacy effect in contextual cueing.

PubMed

Jungé, Justin A; Scholl, Brian J; Chun, Marvin M

2007-01-01

Over repeated exposure to particular visual search displays, subjects are able to implicitly extract regularities that then make search more efficient-a phenomenon known as contextual cueing. Here we explore how the learning involved in contextual cueing is formed, maintained, and updated over experience. During an initial training phase, a group of signal first subjects searched through a series of predictive displays (where distractor locations were perfectly correlated with the target location), followed with no overt break by a series of unpredictive displays (where repeated contexts were uncorrelated with target locations). A second noise first group of subjects encountered the unpredictive displays followed by the predictive displays. Despite the fact that both groups had the same overall exposure to signal and noise, only the signal first group demonstrated subsequent contextual cueing. This primacy effect indicates that initial experience can result in hypotheses about regularities in displays-or the lack thereof-which then become resistant to updating. The absence of regularities in early stages of training even blocked observers from learning predictive regularities later on.

Display technologies for augmented reality

NASA Astrophysics Data System (ADS)

Lee, Byoungho; Lee, Seungjae; Jang, Changwon; Hong, Jong-Young; Li, Gang

2018-02-01

With the virtue of rapid progress in optics, sensors, and computer science, we are witnessing that commercial products or prototypes for augmented reality (AR) are penetrating into the consumer markets. AR is spotlighted as expected to provide much more immersive and realistic experience than ordinary displays. However, there are several barriers to be overcome for successful commercialization of AR. Here, we explore challenging and important topics for AR such as image combiners, enhancement of display performance, and focus cue reproduction. Image combiners are essential to integrate virtual images with real-world. Display performance (e.g. field of view and resolution) is important for more immersive experience and focus cue reproduction may mitigate visual fatigue caused by vergence-accommodation conflict. We also demonstrate emerging technologies to overcome these issues: index-matched anisotropic crystal lens (IMACL), retinal projection displays, and 3D display with focus cues. For image combiners, a novel optical element called IMACL provides relatively wide field of view. Retinal projection displays may enhance field of view and resolution of AR displays. Focus cues could be reconstructed via multi-layer displays and holographic displays. Experimental results of our prototypes are explained.

How is spatial context learning integrated over signal versus noise? A primacy effect in contextual cueing

PubMed Central

Jungé, Justin A.; Scholl, Brian J.; Chun, Marvin M.

2008-01-01

Over repeated exposure to particular visual search displays, subjects are able to implicitly extract regularities that then make search more efficient—a phenomenon known as contextual cueing. Here we explore how the learning involved in contextual cueing is formed, maintained, and updated over experience. During an initial training phase, a group of signal first subjects searched through a series of predictive displays (where distractor locations were perfectly correlated with the target location), followed with no overt break by a series of unpredictive displays (where repeated contexts were uncorrelated with target locations). A second noise first group of subjects encountered the unpredictive displays followed by the predictive displays. Despite the fact that both groups had the same overall exposure to signal and noise, only the signal first group demonstrated subsequent contextual cueing. This primacy effect indicates that initial experience can result in hypotheses about regularities in displays—or the lack thereof—which then become resistant to updating. The absence of regularities in early stages of training even blocked observers from learning predictive regularities later on. PMID:18725966

Non-hierarchical Influence of Visual Form, Touch, and Position Cues on Embodiment, Agency, and Presence in Virtual Reality

PubMed Central

Pritchard, Stephen C.; Zopf, Regine; Polito, Vince; Kaplan, David M.; Williams, Mark A.

2016-01-01

The concept of self-representation is commonly decomposed into three component constructs (sense of embodiment, sense of agency, and sense of presence), and each is typically investigated separately across different experimental contexts. For example, embodiment has been explored in bodily illusions; agency has been investigated in hypnosis research; and presence has been primarily studied in the context of Virtual Reality (VR) technology. Given that each component involves the integration of multiple cues within and across sensory modalities, they may rely on similar underlying mechanisms. However, the degree to which this may be true remains unclear when they are independently studied. As a first step toward addressing this issue, we manipulated a range of cues relevant to these components of self-representation within a single experimental context. Using consumer-grade Oculus Rift VR technology, and a new implementation of the Virtual Hand Illusion, we systematically manipulated visual form plausibility, visual–tactile synchrony, and visual–proprioceptive spatial offset to explore their influence on self-representation. Our results show that these cues differentially influence embodiment, agency, and presence. We provide evidence that each type of cue can independently and non-hierarchically influence self-representation yet none of these cues strictly constrains or gates the influence of the others. We discuss theoretical implications for understanding self-representation as well as practical implications for VR experiment design, including the suitability of consumer-based VR technology in research settings. PMID:27826275

The effects of auditory and visual cues on timing synchronicity for robotic rehabilitation.

PubMed

English, Brittney A; Howard, Ayanna M

2017-07-01

In this paper, we explore how the integration of auditory and visual cues can help teach the timing of motor skills for the purpose of motor function rehabilitation. We conducted a study using Amazon's Mechanical Turk in which 106 participants played a virtual therapy game requiring wrist movements. To validate that our results would translate to trends that could also be observed during robotic rehabilitation sessions, we recreated this experiment with 11 participants using a robotic wrist rehabilitation system as means to control the therapy game. During interaction with the therapy game, users were asked to learn and reconstruct a tapping sequence as defined by musical notes flashing on the screen. Participants were divided into 2 test groups: (1) control: participants only received visual cues to prompt them on the timing sequence, and (2) experimental: participants received both visual and auditory cues to prompt them on the timing sequence. To evaluate performance, the timing and length of the sequence were measured. Performance was determined by calculating the number of trials needed before the participant was able to master the specific aspect of the timing task. In the virtual experiment, the group that received visual and auditory cues was able to master all aspects of the timing task faster than the visual cue only group with p-values < 0.05. This trend was also verified for participants using the robotic arm exoskeleton in the physical experiment.

A variable-collimation display system

NASA Astrophysics Data System (ADS)

Batchko, Robert; Robinson, Sam; Schmidt, Jack; Graniela, Benito

2014-03-01

Two important human depth cues are accommodation and vergence. Normally, the eyes accommodate and converge or diverge in tandem; changes in viewing distance cause the eyes to simultaneously adjust both focus and orientation. However, ambiguity between accommodation and vergence cues is a well-known limitation in many stereoscopic display technologies. This limitation also arises in state-of-the-art full-flight simulator displays. In current full-flight simulators, the out-the-window (OTW) display (i.e., the front cockpit window display) employs a fixed collimated display technology which allows the pilot and copilot to perceive the OTW training scene without angular errors or distortions; however, accommodation and vergence cues are limited to fixed ranges (e.g., ~ 20 m). While this approach works well for long-range, the ambiguity of depth cues at shorter range hinders the pilot's ability to gauge distances in critical maneuvers such as vertical take-off and landing (VTOL). This is the first in a series of papers on a novel, variable-collimation display (VCD) technology that is being developed under NAVY SBIR Topic N121-041 funding. The proposed VCD will integrate with rotary-wing and vertical take-off and landing simulators and provide accurate accommodation and vergence cues for distances ranging from approximately 3 m outside the chin window to ~ 20 m. A display that offers dynamic accommodation and vergence could improve pilot safety and training, and impact other applications presently limited by lack of these depth cues.

Bees without Flowers: Before Peak Bloom, Diverse Native Bees Find Insect-Produced Honeydew Sugars.

PubMed

Meiners, Joan M; Griswold, Terry L; Harris, David J; Ernest, S K Morgan

2017-08-01

Bee foragers respond to complex visual, olfactory, and extrasensory cues to optimize searches for floral rewards. Their abilities to detect and distinguish floral colors, shapes, volatiles, and ultraviolet signals and even gauge nectar availability from changes in floral humidity or electric fields are well studied. Bee foraging behaviors in the absence of floral cues, however, are rarely considered. We observed 42 species of wild bees visiting inconspicuous, nonflowering shrubs during early spring in a protected Mediterranean habitat. We determined experimentally that these bees were accessing sugary honeydew secretions from scale insects without the aid of standard cues. While honeydew use is known among some social Hymenoptera, its use across a diverse community of solitary bees is a novel observation. The widespread ability of native bees to locate and use unadvertised, nonfloral sugars suggests unappreciated sensory mechanisms and/or the existence of an interspecific foraging network among solitary bees that may influence how native bees cope with scarcity of floral resources and increasing environmental change.

Benefits of Accumulating Versus Diminishing Cues in Recall

PubMed Central

Finley, Jason R.; Benjamin, Aaron S.; Hays, Matthew J.; Bjork, Robert A.; Kornell, Nate

2011-01-01

Optimizing learning over multiple retrieval opportunities requires a joint consideration of both the probability and the mnemonic value of a successful retrieval. Previous research has addressed this trade-off by manipulating the schedule of practice trials, suggesting that a pattern of increasingly long lags—“expanding retrieval practice”—may keep retrievals successful while gradually increasing their mnemonic value (Landauer & Bjork, 1978). Here we explore the trade-off issue further using an analogous manipulation of cue informativeness. After being given an initial presentation of English-Iñupiaq word pairs, participants received practice trials across which letters of the target word were either accumulated (AC), diminished (DC), or always fully present. Diminishing cues yielded the highest performance on a final test of cued recall. Additional analyses suggest that AC practice promotes potent (effortful) retrieval at the cost of success, and DC practice promotes successful retrieval at the cost of potency. Experiment 2 revealed that the negative effects of AC practice can be partly ameliorated by providing feedback after each practice trial. PMID:21499516

Determination of depth-viewing volumes for stereo three-dimensional graphic displays

NASA Technical Reports Server (NTRS)

Parrish, Russell V.; Williams, Steven P.

1990-01-01

Real-world, 3-D, pictorial displays incorporating true depth cues via stereopsis techniques offer a potential means of displaying complex information in a natural way to prevent loss of situational awareness and provide increases in pilot/vehicle performance in advanced flight display concepts. Optimal use of stereopsis requires an understanding of the depth viewing volume available to the display designer. Suggested guidelines are presented for the depth viewing volume from an empirical determination of the effective region of stereopsis cueing (at several viewer-CRT screen distances) for a time multiplexed stereopsis display system. The results provide the display designer with information that will allow more effective placement of depth information to enable the full exploitation of stereopsis cueing. Increasing viewer-CRT screen distances provides increasing amounts of usable depth, but with decreasing fields-of-view. A stereopsis hardware system that permits an increased viewer-screen distance by incorporating larger screen sizes or collimation optics to maintain the field-of-view at required levels would provide a much larger stereo depth-viewing volume.

The Cues and Care Trial: A randomized controlled trial of an intervention to reduce maternal anxiety and improve developmental outcomes in very low birthweight infants

PubMed Central

Zelkowitz, Phyllis; Feeley, Nancy; Shrier, Ian; Stremler, Robyn; Westreich, Ruta; Dunkley, David; Steele, Russell; Rosberger, Zeev; Lefebvre, Francine; Papageorgiou, Apostolos

2008-01-01

Background Very low birthweight infants are at risk for deficits in cognitive and language development, as well as attention and behaviour problems. Maternal sensitive behaviour (i.e. awareness of infant cues and appropriate responsiveness to those cues) in interaction with her very low birthweight infant is associated with better outcomes in these domains; however, maternal anxiety interferes with the mother's ability to interact sensitively with her very low birthweight infant. There is a need for brief, cost-effective and timely interventions that address both maternal psychological distress and interactive behaviour. The Cues and Care trial is a randomized controlled trial of an intervention designed to reduce maternal anxiety and promote sensitive interaction in mothers of very low birthweight infants. Methods and design Mothers of singleton infants born at weights below 1500 g are recruited in the neonatal intensive care units of 2 tertiary care hospitals, and are randomly assigned to the experimental (Cues) intervention or to an attention control (Care) condition. The Cues intervention teaches mothers to attend to their own physiological, cognitive, and emotional cues that signal anxiety and worry, and to use cognitive-behavioural strategies to reduce distress. Mothers are also taught to understand infant cues and to respond sensitively to those cues. Mothers in the Care group receive general information about infant care. Both groups have 6 contacts with a trained intervener; 5 of the 6 sessions take place during the infant's hospitalization, and the sixth contact occurs after discharge, in the participant mother's home. The primary outcome is maternal symptoms of anxiety, assessed via self-report questionnaire immediately post-intervention. Secondary outcomes include maternal sensitive behaviour, maternal symptoms of posttraumatic stress, and infant development at 6 months corrected age. Discussion The Cues and Care trial will provide important information on the efficacy of a brief, skills-based intervention to reduce anxiety and increase sensitivity in mothers of very low birthweight infants. A brief intervention of this nature may be more readily implemented as part of standard neonatal intensive care than broad-based, multi-component interventions. By intervening early, we aim to optimize developmental outcomes in these high risk infants. Trial Registration Current Controlled Trials ISRCTN00918472 The Cues and Care Trial: A randomized controlled trial of an intervention to reduce maternal anxiety and improve developmental outcomes in very low birthweight infants PMID:18822128

Quantitative Analysis of Dendritic Cell Haptotaxis.

PubMed

Schwarz, Jan; Sixt, Michael

2016-01-01

Chemokines are the main guidance cues directing leukocyte migration. Opposed to early assumptions, chemokines do not necessarily act as soluble cues but are often immobilized within tissues, e.g., dendritic cell migration toward lymphatic vessels is guided by a haptotactic gradient of the chemokine CCL21. Controlled assay systems to quantitatively study haptotaxis in vitro are still missing. In this chapter, we describe an in vitro haptotaxis assay optimized for the unique properties of dendritic cells. The chemokine CCL21 is immobilized in a bioactive state, using laser-assisted protein adsorption by photobleaching. The cells follow this immobilized CCL21 gradient in a haptotaxis chamber, which provides three dimensionally confined migration conditions. © 2016 Elsevier Inc. All rights reserved.

Nurses' beliefs and values about doing cue-based care in an NICU in Taiwan.

PubMed

Liaw, Jen-Jiuan; Chen, Shu-Yueh; Yin, Ying-Ti

2004-12-01

Although advances in medical technology have increased the survival rate of preterm infants, science is no cure-all for these high-risk patients. A growing number of studies report that caregiving interventions cause physiological and behavioral distress in such infants. The results have prompted changes in caregiving practices, attempting to reduce stress and strengthen protection for the infants, in order to promote their stability and development in the neonatal intensive care unit (NICU) . This study uses qualitative research methods to grasp the richness and diversity of nurses' beliefs and experience in the taking care of preterm infants. Ten groups of questions explore how NICU nurses take care of premature infants, nurses' perspectives on cue-based care, and the extent to which NICU nurses practice cue-based care. The results generated three themes: (1) timely and skillful management of the preterm infants; (2) compassionate and holistic care for the infants and their highly stressed families; and (3) the relationship between good nursing care and meeting the needs of preterm infants, families, physicians, units, and the environment. It is apparent that the approach to care delivery in NICU practice is still clinical-based, and that there are some obstacles to the delivery of cue-based care. The reasons for this include lack of knowledge, incomplete collaboration with team members, and insufficient support from the administrative systems. To improve the quality of nursing care and preterm infant outcomes, it will be necessary to educate NICU nurses on cue-based care, to enhance collaboration among all team members, to reduce their non-nursing workload, and to re-design NICUs for optimal cue-based care.

How microsaccades relate to lateralized ERP components of spatial attention: A co-registration study.

PubMed

Meyberg, Susann; Sommer, Werner; Dimigen, Olaf

2017-05-01

Covert shifts of attention that follow the presentation of a cue are associated with lateralized components in the event-related potential (ERP): the "early directing attention negativity" (EDAN) and the "anterior directing attention negativity" (ADAN). Traditionally, these shifts are thought to take place while gaze is fixated and, thus, in the absence of saccades. However, microsaccades of small amplitude (<1°) occur frequently and involuntarily also during fixation and are closely correlated with spatial attention. To investigate potential links between microsaccades and lateralized ERP components, we simultaneously recorded eye movements and ERPs in a spatial cueing task. As a first major result, we show that both the posterior EDAN and the orientation of microsaccades align more strongly with the location of the task-relevant part of the cue stimulus than with the direction of the attention shift indicated by that cue. A coupling between microsaccades and EDAN was also present on the single-trial level: The EDAN was largest when microsaccades were oriented toward the relevant cue, but absent when microsaccades were oriented away from it, suggesting that EDAN and microsaccades are generated by the same neural network, which selects relevant stimuli and orients behavior toward them. As a second major result, we show that small corneoretinal artifacts from microsaccades, which fall below conventional EOG rejection thresholds, contaminate the measurement of the ADAN. After correcting the EEG for microsaccade-related artifacts with an optimized variant of independent component analysis, ADAN was abolished at frontal sites, but a genuine ADAN was still present at central sites. Thus, the combined measurement of microsaccades and lateralized ERPs sheds new light onto cue-elicited shifts of covert attention. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mixed signals: The effect of conflicting reward- and goal-driven biases on selective attention.

PubMed

Preciado, Daniel; Munneke, Jaap; Theeuwes, Jan

2017-07-01

Attentional selection depends on the interaction between exogenous (stimulus-driven), endogenous (goal-driven), and selection history (experience-driven) factors. While endogenous and exogenous biases have been widely investigated, less is known about their interplay with value-driven attention. The present study investigated the interaction between reward-history and goal-driven biases on perceptual sensitivity (d') and response time (RT) in a modified cueing paradigm presenting two coloured cues, followed by sinusoidal gratings. Participants responded to the orientation of one of these gratings. In Experiment 1, one cue signalled reward availability but was otherwise task irrelevant. In Experiment 2, the same cue signalled reward, and indicated the target's most likely location at the opposite side of the display. This design introduced a conflict between reward-driven biases attracting attention and goal-driven biases directing it away. Attentional effects were examined comparing trials in which cue and target appeared at the same versus opposite locations. Two interstimulus interval (ISI) levels were used to probe the time course of attentional effects. Experiment 1 showed performance benefits at the location of the reward-signalling cue and costs at the opposite for both ISIs, indicating value-driven capture. Experiment 2 showed performance benefits only for the long ISI when the target was at the opposite to the reward-associated cue. At the short ISI, only performance costs were observed. These results reveal the time course of these biases, indicating that reward-driven effects influence attention early but can be overcome later by goal-driven control. This suggests that reward-driven biases are integrated as attentional priorities, just as exogenous and endogenous factors.

Effects of visual cues of object density on perception and anticipatory control of dexterous manipulation.

PubMed

Crajé, Céline; Santello, Marco; Gordon, Andrew M

2013-01-01

Anticipatory force planning during grasping is based on visual cues about the object's physical properties and sensorimotor memories of previous actions with grasped objects. Vision can be used to estimate object mass based on the object size to identify and recall sensorimotor memories of previously manipulated objects. It is not known whether subjects can use density cues to identify the object's center of mass (CM) and create compensatory moments in an anticipatory fashion during initial object lifts to prevent tilt. We asked subjects (n = 8) to estimate CM location of visually symmetric objects of uniform densities (plastic or brass, symmetric CM) and non-uniform densities (mixture of plastic and brass, asymmetric CM). We then asked whether subjects can use density cues to scale fingertip forces when lifting the visually symmetric objects of uniform and non-uniform densities. Subjects were able to accurately estimate an object's center of mass based on visual density cues. When the mass distribution was uniform, subjects could scale their fingertip forces in an anticipatory fashion based on the estimation. However, despite their ability to explicitly estimate CM location when object density was non-uniform, subjects were unable to scale their fingertip forces to create a compensatory moment and prevent tilt on initial lifts. Hefting object parts in the hand before the experiment did not affect this ability. This suggests a dichotomy between the ability to accurately identify the object's CM location for objects with non-uniform density cues and the ability to utilize this information to correctly scale their fingertip forces. These results are discussed in the context of possible neural mechanisms underlying sensorimotor integration linking visual cues and anticipatory control of grasping.

Situational cues and momentary food environment predict everyday eating behavior in adults with overweight and obesity.

PubMed

Elliston, Katherine G; Ferguson, Stuart G; Schüz, Natalie; Schüz, Benjamin

2017-04-01

Individual eating behavior is a risk factor for obesity and highly dependent on internal and external cues. Many studies also suggest that the food environment (i.e., food outlets) influences eating behavior. This study therefore examines the momentary food environment (at the time of eating) and the role of cues simultaneously in predicting everyday eating behavior in adults with overweight and obesity. Intensive longitudinal study using ecological momentary assessment (EMA) over 14 days in 51 adults with overweight and obesity (average body mass index = 30.77; SD = 4.85) with a total of 745 participant days of data. Multiple daily assessments of eating (meals, high- or low-energy snacks) and randomly timed assessments. Cues and the momentary food environment were assessed during both assessment types. Random effects multinomial logistic regression shows that both internal (affect) and external (food availability, social situation, observing others eat) cues were associated with increased likelihood of eating. The momentary food environment predicted meals and snacking on top of cues, with a higher likelihood of high-energy snacks when fast food restaurants were close by (odds ratio [OR] = 1.89, 95% confidence interval [CI] = 1.22, 2.93) and a higher likelihood of low-energy snacks in proximity to supermarkets (OR = 2.29, 95% CI = 1.38, 3.82). Real-time eating behavior, both in terms of main meals and snacks, is associated with internal and external cues in adults with overweight and obesity. In addition, perceptions of the momentary food environment influence eating choices, emphasizing the importance of an integrated perspective on eating behavior and obesity prevention. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Cue reliability and a landmark stability heuristic determine relative weighting between egocentric and allocentric visual information in memory-guided reach.

PubMed

Byrne, Patrick A; Crawford, J Douglas

2010-06-01

It is not known how egocentric visual information (location of a target relative to the self) and allocentric visual information (location of a target relative to external landmarks) are integrated to form reach plans. Based on behavioral data from rodents and humans we hypothesized that the degree of stability in visual landmarks would influence the relative weighting. Furthermore, based on numerous cue-combination studies we hypothesized that the reach system would act like a maximum-likelihood estimator (MLE), where the reliability of both cues determines their relative weighting. To predict how these factors might interact we developed an MLE model that weighs egocentric and allocentric information based on their respective reliabilities, and also on an additional stability heuristic. We tested the predictions of this model in 10 human subjects by manipulating landmark stability and reliability (via variable amplitude vibration of the landmarks and variable amplitude gaze shifts) in three reach-to-touch tasks: an egocentric control (reaching without landmarks), an allocentric control (reaching relative to landmarks), and a cue-conflict task (involving a subtle landmark "shift" during the memory interval). Variability from all three experiments was used to derive parameters for the MLE model, which was then used to simulate egocentric-allocentric weighting in the cue-conflict experiment. As predicted by the model, landmark vibration--despite its lack of influence on pointing variability (and thus allocentric reliability) in the control experiment--had a strong influence on egocentric-allocentric weighting. A reduced model without the stability heuristic was unable to reproduce this effect. These results suggest heuristics for extrinsic cue stability are at least as important as reliability for determining cue weighting in memory-guided reaching.

The point of entry contributes to the organization of exploratory behavior of rats on an open field: an example of spontaneous episodic memory.

PubMed

Nemati, Farshad; Whishaw, Ian Q

2007-08-22

The exploratory behavior of rats on an open field is organized in that animals spend disproportionate amounts of time at certain locations, termed home bases, which serve as centers for excursions. Although home bases are preferentially formed near distinctive cues, including visual cues, animals also visit and pause and move slowly, or linger, at many other locations in a test environment. In order to further examine the organization of exploratory behavior, the present study examined the influence of the point of entry on animals placed on an open field table that was illuminated either by room light or infrared light (a wavelength in which they cannot see) and near which, or on which, distinctive cues were placed. The main findings were that in both room light and infrared light tests, rats visited and lingered at the point of entry significantly more often than comparative control locations. Although the rats also visited and lingered in the vicinity of salient visual cues, the point of entry still remained a focus of visits. Finally, the preference for the point of entry increased as a function of salience of the cues marking that location. That the point of entry influences the organization of exploratory behavior is discussed in relation to the idea that the exploratory behavior of the rat is directed toward optimizing security as well as forming a spatial representation of the environment.

AGCVIII Kinases: at the crossroads of cellular signaling

USDA-ARS?s Scientific Manuscript database

AGCVIII kinases regulate diverse developmental and cellular processes in plants. As putative mediators of secondary messengers, AGCVIII kinases potentially integrate developmental and environmental cues into specific cellular responses through substrate phosphorylation. Here we discuss the functiona...

Brain response during the M170 time interval is sensitive to socially relevant information.

PubMed

Arviv, Oshrit; Goldstein, Abraham; Weeting, Janine C; Becker, Eni S; Lange, Wolf-Gero; Gilboa-Schechtman, Eva

2015-11-01

Deciphering the social meaning of facial displays is a highly complex neurological process. The M170, an event related field component of MEG recording, like its EEG counterpart N170, was repeatedly shown to be associated with structural encoding of faces. However, the scope of information encoded during the M170 time window is still being debated. We investigated the neuronal origin of facial processing of integrated social rank cues (SRCs) and emotional facial expressions (EFEs) during the M170 time interval. Participants viewed integrated facial displays of emotion (happy, angry, neutral) and SRCs (indicated by upward, downward, or straight head tilts). We found that the activity during the M170 time window is sensitive to both EFEs and SRCs. Specifically, highly prominent activation was observed in response to SRC connoting dominance as compared to submissive or egalitarian head cues. Interestingly, the processing of EFEs and SRCs appeared to rely on different circuitry. Our findings suggest that vertical head tilts are processed not only for their sheer structural variance, but as social information. Exploring the temporal unfolding and brain localization of non-verbal cues processing may assist in understanding the functioning of the social rank biobehavioral system. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evidence for enhanced multi-component behaviour in Tourette syndrome - an EEG study.

PubMed

Brandt, Valerie C; Stock, Ann-Kathrin; Münchau, Alexander; Beste, Christian

2017-08-10

Evidence suggests that Tourette syndrome is characterized by an increase in dopamine transmission and structural as well as functional changes in fronto-striatal circuits that might lead to enhanced multi-component behaviour integration. Behavioural and neurophysiological data regarding multi-component behaviour was collected from 15 patients with Tourette syndrome (mean age = 30.40 ± 11.10) and 15 healthy controls (27.07 ± 5.44), using the stop-change task. In this task, participants are asked to sometimes withhold responses to a Go stimulus (stop cue) and change hands to respond to an alternative Go stimulus (change cue). Different onset asynchronies between stop and change cues were implemented (0 and 300 ms) in order to vary task difficulty. Tourette patients responded more accurately than healthy controls when there was no delay between stop and change stimulus, while there was no difference in the 300 ms delay condition. This performance advantage was reflected in a smaller P3 event related potential. Enhanced multi-component behaviour in Tourette syndrome is likely based on an enhanced ability to integrate information from multiple sources and translate it into an appropriate response sequence. This may be a consequence of chronic tic control in these patients, or a known fronto-striatal networks hyperconnectivity in Tourette syndrome.

Information theory and the neuropeptidergic regulation of seasonal reproduction in mammals and birds

PubMed Central

Stevenson, Tyler J.; Ball, Gregory F.

2011-01-01

Seasonal breeding in the temperate zone is a dramatic example of a naturally occurring change in physiology and behaviour. Cues that predict periods of environmental amelioration favourable for breeding must be processed by the brain so that the appropriate responses in reproductive physiology can be implemented. The neural integration of several environmental cues converges on discrete hypothalamic neurons in order to regulate reproductive physiology. Gonadotrophin-releasing hormone-1 (GnRH1) and Kisspeptin (Kiss1) neurons in avian and mammalian species, respectively, show marked variation in expression that is positively associated with breeding state. We applied the constancy/contingency model of predictability to investigate how GnRH1 and Kiss1 integrate different environmental cues to regulate reproduction. We show that variation in GnRH1 from a highly seasonal avian species exhibits a predictive change that is primarily based on contingency information. Opportunistic species have low measures of predictability and exhibit a greater contribution of constancy information that is sex-dependent. In hamsters, Kiss1 exhibited a predictive change in expression that was predominantly contingency information and is anatomically localized. The model applied here provides a framework for studies geared towards determining the impact of variation in climate patterns to reproductive success in vertebrate species. PMID:21208957

How chimpanzees integrate sensory information to select figs.

PubMed

Dominy, Nathaniel J; Yeakel, Justin D; Bhat, Uttam; Ramsden, Lawrence; Wrangham, Richard W; Lucas, Peter W

2016-06-06

Figs are keystone resources that sustain chimpanzees when preferred fruits are scarce. Many figs retain a green(ish) colour throughout development, a pattern that causes chimpanzees to evaluate edibility on the basis of achromatic accessory cues. Such behaviour is conspicuous because it entails a succession of discrete sensory assessments, including the deliberate palpation of individual figs, a task that requires advanced visuomotor control. These actions are strongly suggestive of domain-specific information processing and decision-making, and they call attention to a potential selective force on the origin of advanced manual prehension and digital dexterity during primate evolution. To explore this concept, we report on the foraging behaviours of chimpanzees and the spectral, chemical and mechanical properties of figs, with cutting tests revealing ease of fracture in the mouth. By integrating the ability of different sensory cues to predict fructose content in a Bayesian updating framework, we quantified the amount of information gained when a chimpanzee successively observes, palpates and bites the green figs of Ficus sansibarica. We found that the cue eliciting ingestion was not colour or size, but fig mechanics (including toughness estimates from wedge tests), which relays higher-quality information on fructose concentrations than colour vision. This result explains why chimpanzees evaluate green figs by palpation and dental incision, actions that could explain the adaptive origins of advanced manual prehension.

Visuo-vestibular interaction: predicting the position of a visual target during passive body rotation.

PubMed

Mackrous, I; Simoneau, M

2011-11-10

Following body rotation, optimal updating of the position of a memorized target is attained when retinal error is perceived and corrective saccade is performed. Thus, it appears that these processes may enable the calibration of the vestibular system by facilitating the sharing of information between both reference frames. Here, it is assessed whether having sensory information regarding body rotation in the target reference frame could enhance an individual's learning rate to predict the position of an earth-fixed target. During rotation, participants had to respond when they felt their body midline had crossed the position of the target and received knowledge of result. During practice blocks, for two groups, visual cues were displayed in the same reference frame of the target, whereas a third group relied on vestibular information (vestibular-only group) to predict the location of the target. Participants, unaware of the role of the visual cues (visual cues group), learned to predict the location of the target and spatial error decreased from 16.2 to 2.0°, reflecting a learning rate of 34.08 trials (determined from fitting a falling exponential model). In contrast, the group aware of the role of the visual cues (explicit visual cues group) showed a faster learning rate (i.e. 2.66 trials) but similar final spatial error 2.9°. For the vestibular-only group, similar accuracy was achieved (final spatial error of 2.3°), but their learning rate was much slower (i.e. 43.29 trials). Transferring to the Post-test (no visual cues and no knowledge of result) increased the spatial error of the explicit visual cues group (9.5°), but it did not change the performance of the vestibular group (1.2°). Overall, these results imply that cognition assists the brain in processing the sensory information within the target reference frame. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

Temporal Integration of Auditory Information Is Invariant to Temporal Grouping Cues

PubMed

Liu, Andrew S K; Tsunada, Joji; Gold, Joshua I; Cohen, Yale E

2015-01-01

Auditory perception depends on the temporal structure of incoming acoustic stimuli. Here, we examined whether a temporal manipulation that affects the perceptual grouping also affects the time dependence of decisions regarding those stimuli. We designed a novel discrimination task that required human listeners to decide whether a sequence of tone bursts was increasing or decreasing in frequency. We manipulated temporal perceptual-grouping cues by changing the time interval between the tone bursts, which led to listeners hearing the sequences as a single sound for short intervals or discrete sounds for longer intervals. Despite these strong perceptual differences, this manipulation did not affect the efficiency of how auditory information was integrated over time to form a decision. Instead, the grouping manipulation affected subjects' speed-accuracy trade-offs. These results indicate that the temporal dynamics of evidence accumulation for auditory perceptual decisions can be invariant to manipulations that affect the perceptual grouping of the evidence.

Overhearers Use Addressee Backchannels in Dialog Comprehension.

PubMed

Tolins, Jackson; Fox Tree, Jean E

2016-08-01

Observing others in conversation is a common format for comprehending language, yet little work has been done to understand dialog comprehension. We tested whether overhearers use addressee backchannels as predictive cues for how to integrate information across speaker turns during comprehension of spontaneously produced collaborative narration. In Experiment 1, words that followed specific backchannels (e.g., really, oh) were recognized more slowly than words that followed either generic backchannels (e.g., uh huh, mhm) or pauses. In Experiment 2, we found that when the turn after the backchannel was a continuation of the narrative, specific backchannels prompted the fastest verification of prior information. When the turn after was an elaboration, they prompted the slowest, indicating that overhearers took specific backchannels as cues to integrate preceding talk with subsequent talk. These findings demonstrate that overhearers capitalize on the predictive relationship between backchannels and the development of speakers' talk, coordinating information across conversational roles. Copyright © 2015 Cognitive Science Society, Inc.

Human body segmentation via data-driven graph cut.

PubMed

Li, Shifeng; Lu, Huchuan; Shao, Xingqing

2014-11-01

Human body segmentation is a challenging and important problem in computer vision. Existing methods usually entail a time-consuming training phase for prior knowledge learning with complex shape matching for body segmentation. In this paper, we propose a data-driven method that integrates top-down body pose information and bottom-up low-level visual cues for segmenting humans in static images within the graph cut framework. The key idea of our approach is first to exploit human kinematics to search for body part candidates via dynamic programming for high-level evidence. Then, by using the body parts classifiers, obtaining bottom-up cues of human body distribution for low-level evidence. All the evidence collected from top-down and bottom-up procedures are integrated in a graph cut framework for human body segmentation. Qualitative and quantitative experiment results demonstrate the merits of the proposed method in segmenting human bodies with arbitrary poses from cluttered backgrounds.

Impaired force control in writer's cramp showing a bilateral deficit in sensorimotor integration.

PubMed

Bleton, Jean-Pierre; Teremetz, Maxime; Vidailhet, Marie; Mesure, Serge; Maier, Marc A; Lindberg, Påvel G

2014-01-01

Abnormal cortical processing of sensory inputs has been found bilaterally in writer's cramp (WC). This study tested the hypothesis that patients with WC have an impaired ability to adjust grip forces according to visual and somatosensory cues in both hands. A unimanual visuomotor force-tracking task and a bimanual sense of effort force-matching task were performed by WC patients and healthy controls. In visuomotor tracking, WC patients showed increased error, greater variability, and longer release duration than controls. In the force-matching task, patients underestimated, whereas controls overestimated, the force applied in the other hand. Visuomotor tracking and force matching were equally impaired in both the symptomatic and nonsymptomatic hand in WC patients. This study provides evidence of bilaterally impaired grip-force control in WC, when using visual or sense of effort cues. This suggests a generalized subclinical deficit in sensorimotor integration in WC. Copyright © 2013 Movement Disorder Society.

Feature bindings endure without attention: evidence from an explicit recall task.

PubMed

Gajewski, Daniel A; Brockmole, James R

2006-08-01

Are integrated objects the unit of capacity of visual working memory, or is continued attention needed to maintain bindings between independently stored features? In a delayed recall task, participants reported the color and shape of a probed item from a memory array. During the delay, attention was manipulated with an exogenous cue. Recall was elevated at validly cued positions, indicating that the cue affected item memory. On invalid trials, participants most frequently recalled either both features (perfect object memory) or neither of the two features (no object memory); the frequency with which only one feature was recalled was significantly lower than predicted by feature independence as determined in a single-feature recall task. These data do not support the view that features are remembered independently when attention is withdrawn. Instead, integrated objects are stored in visual working memory without need for continued attention.

Integrating body movement into attractiveness research.

PubMed

Fink, Bernhard; Weege, Bettina; Neave, Nick; Pham, Michael N; Shackelford, Todd K

2015-01-01

People judge attractiveness and make trait inferences from the physical appearance of others, and research reveals high agreement among observers making such judgments. Evolutionary psychologists have argued that interest in physical appearance and beauty reflects adaptations that motivate the search for desirable qualities in a potential partner. Although men more than women value the physical appearance of a partner, appearance universally affects social perception in both sexes. Most studies of attractiveness perceptions have focused on third party assessments of static representations of the face and body. Corroborating evidence suggests that body movement, such as dance, also conveys information about mate quality. Here we review evidence that dynamic cues (e.g., gait, dance) also influence perceptions of mate quality, including personality traits, strength, and overall attractiveness. We recommend that attractiveness research considers the informational value of body movement in addition to static cues, to present an integrated perspective on human social perception.

A Forward Genetic Screen for Molecules Involved in Pheromone-Induced Dauer Formation in Caenorhabditis elegans.

PubMed

Neal, Scott J; Park, JiSoo; DiTirro, Danielle; Yoon, Jason; Shibuya, Mayumi; Choi, Woochan; Schroeder, Frank C; Butcher, Rebecca A; Kim, Kyuhyung; Sengupta, Piali

2016-05-03

Animals must constantly assess their surroundings and integrate sensory cues to make appropriate behavioral and developmental decisions. Pheromones produced by conspecific individuals provide critical information regarding environmental conditions. Ascaroside pheromone concentration and composition are instructive in the decision of Caenorhabditis elegans to either develop into a reproductive adult or enter into the stress-resistant alternate dauer developmental stage. Pheromones are sensed by a small set of sensory neurons, and integrated with additional environmental cues, to regulate neuroendocrine signaling and dauer formation. To identify molecules required for pheromone-induced dauer formation, we performed an unbiased forward genetic screen and identified phd (pheromone response-defective dauer) mutants. Here, we describe new roles in dauer formation for previously identified neuronal molecules such as the WD40 domain protein QUI-1 and MACO-1 Macoilin, report new roles for nociceptive neurons in modulating pheromone-induced dauer formation, and identify tau tubulin kinases as new genes involved in dauer formation. Thus, phd mutants define loci required for the detection, transmission, or integration of pheromone signals in the regulation of dauer formation. Copyright © 2016 Neal et al.

Control of a haptic gear shifting assistance device utilizing a magnetorheological clutch

NASA Astrophysics Data System (ADS)

Han, Young-Min; Choi, Seung-Bok

2014-10-01

This paper proposes a haptic clutch driven gear shifting assistance device that can help when the driver shifts the gear of a transmission system. In order to achieve this goal, a magnetorheological (MR) fluid-based clutch is devised to be capable of the rotary motion of an accelerator pedal to which the MR clutch is integrated. The proposed MR clutch is then manufactured, and its transmission torque is experimentally evaluated according to the magnetic field intensity. The manufactured MR clutch is integrated with the accelerator pedal to transmit a haptic cue signal to the driver. The impending control issue is to cue the driver to shift the gear via the haptic force. Therefore, a gear-shifting decision algorithm is constructed by considering the vehicle engine speed concerned with engine combustion dynamics, vehicle dynamics and driving resistance. Then, the algorithm is integrated with a compensation strategy for attaining the desired haptic force. In this work, the compensator is also developed and implemented through the discrete version of the inverse hysteretic model. The control performances, such as the haptic force tracking responses and fuel consumption, are experimentally evaluated.

Biased migration of confined neutrophil-like cells in asymmetric hydraulic environments.

PubMed

Prentice-Mott, Harrison V; Chang, Chi-Han; Mahadevan, L; Mitchison, Timothy J; Irimia, Daniel; Shah, Jagesh V

2013-12-24

Cells integrate multiple measurement modalities to navigate their environment. Soluble and substrate-bound chemical gradients and physical cues have all been shown to influence cell orientation and migration. Here we investigate the role of asymmetric hydraulic pressure in directional sensing. Cells confined in microchannels identified and chose a path of lower hydraulic resistance in the absence of chemical cues. In a bifurcating channel with asymmetric hydraulic resistances, this choice was preceded by the elaboration of two leading edges with a faster extension rate along the lower resistance channel. Retraction of the "losing" edge appeared to precipitate a final choice of direction. The pressure differences altering leading edge protrusion rates were small, suggesting weak force generation by leading edges. The response to the physical asymmetry was able to override a dynamically generated chemical cue. Motile cells may use this bias as a result of hydraulic resistance, or "barotaxis," in concert with chemotaxis to navigate complex environments.

Ventral pallidal encoding of reward-seeking behavior depends on the underlying associative structure

PubMed Central

Stout, Nakura; Acs, Deanna

2018-01-01

Despite its being historically conceptualized as a motor expression site, emerging evidence suggests the ventral pallidum (VP) plays a more active role in integrating information to generate motivation. Here, we investigated whether rat VP cue responses would encode and contribute similarly to the vigor of reward-seeking behaviors trained under Pavlovian versus instrumental contingencies, when these behavioral responses consist of superficially similar locomotor response patterns but may reflect distinct underlying decision-making processes. We find that cue-elicited activity in many VP neurons predicts the latency of instrumental reward seeking, but not of Pavlovian response latency. Further, disruption of VP signaling increases the latency of instrumental but not Pavlovian reward seeking. This suggests that VP encoding of and contributions to response vigor are specific to the ability of incentive cues to invigorate reward-seeking behaviors upon which reward delivery is contingent. PMID:29565248

Mothers' multimodal information processing is modulated by multimodal interactions with their infants.

PubMed

Tanaka, Yukari; Fukushima, Hirokata; Okanoya, Kazuo; Myowa-Yamakoshi, Masako

2014-10-17

Social learning in infancy is known to be facilitated by multimodal (e.g., visual, tactile, and verbal) cues provided by caregivers. In parallel with infants' development, recent research has revealed that maternal neural activity is altered through interaction with infants, for instance, to be sensitive to infant-directed speech (IDS). The present study investigated the effect of mother- infant multimodal interaction on maternal neural activity. Event-related potentials (ERPs) of mothers were compared to non-mothers during perception of tactile-related words primed by tactile cues. Only mothers showed ERP modulation when tactile cues were incongruent with the subsequent words, and only when the words were delivered with IDS prosody. Furthermore, the frequency of mothers' use of those words was correlated with the magnitude of ERP differentiation between congruent and incongruent stimuli presentations. These results suggest that mother-infant daily interactions enhance multimodal integration of the maternal brain in parenting contexts.

Temporal and Rate Coding for Discrete Event Sequences in the Hippocampus.

PubMed

Terada, Satoshi; Sakurai, Yoshio; Nakahara, Hiroyuki; Fujisawa, Shigeyoshi

2017-06-21

Although the hippocampus is critical to episodic memory, neuronal representations supporting this role, especially relating to nonspatial information, remain elusive. Here, we investigated rate and temporal coding of hippocampal CA1 neurons in rats performing a cue-combination task that requires the integration of sequentially provided sound and odor cues. The majority of CA1 neurons displayed sensory cue-, combination-, or choice-specific (simply, "event"-specific) elevated discharge activities, which were sustained throughout the event period. These event cells underwent transient theta phase precession at event onset, followed by sustained phase locking to the early theta phases. As a result of this unique single neuron behavior, the theta sequences of CA1 cell assemblies of the event sequences had discrete representations. These results help to update the conceptual framework for space encoding toward a more general model of episodic event representations in the hippocampus. Copyright © 2017 Elsevier Inc. All rights reserved.

Mothers' multimodal information processing is modulated by multimodal interactions with their infants

PubMed Central

Tanaka, Yukari; Fukushima, Hirokata; Okanoya, Kazuo; Myowa-Yamakoshi, Masako

2014-01-01

Social learning in infancy is known to be facilitated by multimodal (e.g., visual, tactile, and verbal) cues provided by caregivers. In parallel with infants' development, recent research has revealed that maternal neural activity is altered through interaction with infants, for instance, to be sensitive to infant-directed speech (IDS). The present study investigated the effect of mother- infant multimodal interaction on maternal neural activity. Event-related potentials (ERPs) of mothers were compared to non-mothers during perception of tactile-related words primed by tactile cues. Only mothers showed ERP modulation when tactile cues were incongruent with the subsequent words, and only when the words were delivered with IDS prosody. Furthermore, the frequency of mothers' use of those words was correlated with the magnitude of ERP differentiation between congruent and incongruent stimuli presentations. These results suggest that mother-infant daily interactions enhance multimodal integration of the maternal brain in parenting contexts. PMID:25322936

The metamorphosis of the statistical segmentation output: lexicalization during artificial language learning.

PubMed

Fernandes, Tânia; Kolinsky, Régine; Ventura, Paulo

2009-09-01

This study combined artificial language learning (ALL) with conventional experimental techniques to test whether statistical speech segmentation outputs are integrated into adult listeners' mental lexicon. Lexicalization was assessed through inhibitory effects of novel neighbors (created by the parsing process) on auditory lexical decisions to real words. Both immediately after familiarization and post-one week, ALL outputs were lexicalized only when the cues available during familiarization (transitional probabilities and wordlikeness) suggested the same parsing (Experiments 1 and 3). No lexicalization effect occurred with incongruent cues (Experiments 2 and 4). Yet, ALL differed from chance, suggesting a dissociation between item knowledge and lexicalization. Similarly contrasted results were found when frequency of occurrence of the stimuli was equated during familiarization (Experiments 3 and 4). Our findings thus indicate that ALL outputs may be lexicalized as far as the segmentation cues are congruent, and that this process cannot be accounted for by raw frequency.

Brain networks engaged in audiovisual integration during speech perception revealed by persistent homology-based network filtration.

PubMed

Kim, Heejung; Hahm, Jarang; Lee, Hyekyoung; Kang, Eunjoo; Kang, Hyejin; Lee, Dong Soo

2015-05-01

The human brain naturally integrates audiovisual information to improve speech perception. However, in noisy environments, understanding speech is difficult and may require much effort. Although the brain network is supposed to be engaged in speech perception, it is unclear how speech-related brain regions are connected during natural bimodal audiovisual or unimodal speech perception with counterpart irrelevant noise. To investigate the topological changes of speech-related brain networks at all possible thresholds, we used a persistent homological framework through hierarchical clustering, such as single linkage distance, to analyze the connected component of the functional network during speech perception using functional magnetic resonance imaging. For speech perception, bimodal (audio-visual speech cue) or unimodal speech cues with counterpart irrelevant noise (auditory white-noise or visual gum-chewing) were delivered to 15 subjects. In terms of positive relationship, similar connected components were observed in bimodal and unimodal speech conditions during filtration. However, during speech perception by congruent audiovisual stimuli, the tighter couplings of left anterior temporal gyrus-anterior insula component and right premotor-visual components were observed than auditory or visual speech cue conditions, respectively. Interestingly, visual speech is perceived under white noise by tight negative coupling in the left inferior frontal region-right anterior cingulate, left anterior insula, and bilateral visual regions, including right middle temporal gyrus, right fusiform components. In conclusion, the speech brain network is tightly positively or negatively connected, and can reflect efficient or effortful processes during natural audiovisual integration or lip-reading, respectively, in speech perception.

Modifying Parents' Perceptions of Their Child's Developmental Progress: An Approach to Creating Optimal Learning Environments.

ERIC Educational Resources Information Center

Diamond, Karen E.; Reed, Deborah J.

A program to help parents understand their child's developmental level was evaluated with 13 handicapped infants and their mothers. The intervention sought to increase parents' overall understanding of child development, improve their observational skills, and help them adjust their interactions by taking cues from the child's responses. Mental…

Pilot/vehicle model analysis of visual and motion cue requirements in flight simulation. [helicopter hovering

NASA Technical Reports Server (NTRS)

Baron, S.; Lancraft, R.; Zacharias, G.

1980-01-01

The optimal control model (OCM) of the human operator is used to predict the effect of simulator characteristics on pilot performance and workload. The piloting task studied is helicopter hover. Among the simulator characteristics considered were (computer generated) visual display resolution, field of view and time delay.

The Amygdalo-Nigrostriatal Network Is Critical for an Optimal Temporal Performance

ERIC Educational Resources Information Center

Es-seddiqi, Mouna; El Massioui, Nicole; Samson, Nathalie; Brown, Bruce L.; Doyère, Valérie

2016-01-01

The amygdalo-nigrostriatal (ANS) network plays an essential role in enhanced attention to significant events. Interval timing requires attention to temporal cues. We assessed rats having a disconnected ANS network, due to contralateral lesions of the medial central nucleus of the amygdala (CEm) and dopaminergic afferents to the lateral striatum,…

A practical guide to microfluidic perfusion culture of adherent mammalian cells.

PubMed

Kim, Lily; Toh, Yi-Chin; Voldman, Joel; Yu, Hanry

2007-06-01

Culturing cells at microscales allows control over microenvironmental cues, such as cell-cell and cell-matrix interactions; the potential to scale experiments; the use of small culture volumes; and the ability to integrate with microsystem technologies for on-chip experimentation. Microfluidic perfusion culture in particular allows controlled delivery and removal of soluble biochemical molecules in the extracellular microenvironment, and controlled application of mechanical forces exerted via fluid flow. There are many challenges to designing and operating a robust microfluidic perfusion culture system for routine culture of adherent mammalian cells. The current literature on microfluidic perfusion culture treats microfluidic design, device fabrication, cell culture, and micro-assays independently. Here we systematically present and discuss important design considerations in the context of the entire microfluidic perfusion culture system. These design considerations include the choice of materials, culture configurations, microfluidic network fabrication and micro-assays. We also present technical issues such as sterilization; seeding cells in both 2D and 3D configurations; and operating the system under optimized mass transport and shear stress conditions, free of air-bubbles. The integrative and systematic treatment of the microfluidic system design and fabrication, cell culture, and micro-assays provides novices with an effective starting point to build and operate a robust microfludic perfusion culture system for various applications.

Parasites, info-disruption, and the ecology of fear.

PubMed

Rohr, Jason R; Swan, Autumn; Raffel, Thomas R; Hudson, Peter J

2009-03-01

There is growing interest in the ecological consequences of fear, as evidenced by the numerous studies on the nonconsumptive, trait-mediated effects of predators. Parasitism, however, has yet to be fully integrated into research on the ecology of fear, despite it having direct negative and often lethal effects on hosts and being the most common life history strategy on the planet. This might at least be partly due to the traditional, but untested, assumption that anti-parasite responses are weak relative to anti-predator responses. To test this hypothesis, we quantified the activity and location responses of Bufo americanus tadpoles to one of six chemical cues: water; cercariae of Echinostoma trivolvis, a trematode which infects and can kill amphibians; a snail releasing E. trivolvis cercariae; an uninfected snail; food; or conspecific alarm chemicals signaling predation. There is also literature encouraging research on the context dependency and pollution-induced disruption of fear responses. Consequently, before quantifying responses to the chemical cues, half of the B. americanus were exposed to the herbicide atrazine (201 microg/l for 4 days), a reported inhibitor of fear responses in fish. Tadpoles were attracted to food, were indifferent to an uninfected snail, avoided alarm chemicals, and exhibited avoidance and elevated activity in response to a snail shedding cercariae and cercariae alone. Atrazine had no detectable effects on B. americanus' responses to the tested cues despite the use of a higher concentration and longer exposure duration than has been repeatedly shown to inhibit chemical cue detection in fish. The magnitude of anti-parasite and anti-predator responses were qualitatively similar, suggesting that the fear of disease and its ecological consequences could be comparable to that of predation. Consequently, we call for a greater integration of parasites into research on the ecology of fear and trait-mediated indirect effects.

Non-rigid, but not rigid, motion interferes with the processing of structural face information in developmental prosopagnosia.

PubMed

Maguinness, Corrina; Newell, Fiona N

2015-04-01

There is growing evidence to suggest that facial motion is an important cue for face recognition. However, it is poorly understood whether motion is integrated with facial form information or whether it provides an independent cue to identity. To provide further insight into this issue, we compared the effect of motion on face perception in two developmental prosopagnosics and age-matched controls. Participants first learned faces presented dynamically (video), or in a sequence of static images, in which rigid (viewpoint) or non-rigid (expression) changes occurred. Immediately following learning, participants were required to match a static face image to the learned face. Test face images varied by viewpoint (Experiment 1) or expression (Experiment 2) and were learned or novel face images. We found similar performance across prosopagnosics and controls in matching facial identity across changes in viewpoint when the learned face was shown moving in a rigid manner. However, non-rigid motion interfered with face matching across changes in expression in both individuals with prosopagnosia compared to the performance of control participants. In contrast, non-rigid motion did not differentially affect the matching of facial expressions across changes in identity for either prosopagnosics (Experiment 3). Our results suggest that whilst the processing of rigid motion information of a face may be preserved in developmental prosopagnosia, non-rigid motion can specifically interfere with the representation of structural face information. Taken together, these results suggest that both form and motion cues are important in face perception and that these cues are likely integrated in the representation of facial identity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Proprioceptive Distance Cues Restore Perfect Size Constancy in Grasping, but Not Perception, When Vision Is Limited.

PubMed

Chen, Juan; Sperandio, Irene; Goodale, Melvyn Alan

2018-03-19

Our brain integrates information from multiple modalities in the control of behavior. When information from one sensory source is compromised, information from another source can compensate for the loss. What is not clear is whether the nature of this multisensory integration and the re-weighting of different sources of sensory information are the same across different control systems. Here, we investigated whether proprioceptive distance information (position sense of body parts) can compensate for the loss of visual distance cues that support size constancy in perception (mediated by the ventral visual stream) [1, 2] versus size constancy in grasping (mediated by the dorsal visual stream) [3-6], in which the real-world size of an object is computed despite changes in viewing distance. We found that there was perfect size constancy in both perception and grasping in a full-viewing condition (lights on, binocular viewing) and that size constancy in both tasks was dramatically disrupted in the restricted-viewing condition (lights off; monocular viewing of the same but luminescent object through a 1-mm pinhole). Importantly, in the restricted-viewing condition, proprioceptive cues about viewing distance originating from the non-grasping limb (experiment 1) or the inclination of the torso and/or the elbow angle of the grasping limb (experiment 2) compensated for the loss of visual distance cues to enable a complete restoration of size constancy in grasping but only a modest improvement of size constancy in perception. This suggests that the weighting of different sources of sensory information varies as a function of the control system being used. Copyright © 2018 Elsevier Ltd. All rights reserved.

Integration of celestial compass cues in the central complex of the locust brain.

PubMed

Pegel, Uta; Pfeiffer, Keram; Homberg, Uwe

2018-01-29

Many insects rely on celestial compass cues such as the polarization pattern of the sky for spatial orientation. In the desert locust, the central complex (CX) houses multiple sets of neurons, sensitive to the oscillation plane of polarized light and thus probably acts as an internal polarization compass. We investigated whether other sky compass cues like direct sunlight or the chromatic gradient of the sky might contribute to this compass. We recorded from polarization-sensitive CX neurons while an unpolarized green or ultraviolet light spot was moved around the head of the animal. All types of neuron that were sensitive to the plane of polarization ( E -vector) above the animal also responded to the unpolarized light spots in an azimuth-dependent way. The tuning to the unpolarized light spots was independent of wavelength, suggesting that the neurons encode solar azimuth based on direct sunlight and not on the sky chromatic gradient. Two cell types represented the natural 90 deg relationship between solar azimuth and zenithal E -vector orientation, providing evidence to suggest that solar azimuth information supports the internal polarization compass. Most neurons showed advances in their tuning to the E -vector and the unpolarized light spots dependent on rotation direction, consistent with anticipatory signaling. The amplitude of responses and its variability were dependent on the level of background firing, possibly indicating different internal states. The integration of polarization and solar azimuth information strongly suggests that besides the polarization pattern of the sky, direct sunlight might be an important cue for sky compass navigation in the locust. © 2018. Published by The Company of Biologists Ltd.

Compass cues used by a nocturnal bull ant, Myrmecia midas.

PubMed

Freas, Cody A; Narendra, Ajay; Cheng, Ken

2017-05-01

Ants use both terrestrial landmarks and celestial cues to navigate to and from their nest location. These cues persist even as light levels drop during the twilight/night. Here, we determined the compass cues used by a nocturnal bull ant, Myrmecia midas , in which the majority of individuals begin foraging during the evening twilight period. Myrmecia midas foragers with vectors of ≤5   m when displaced to unfamiliar locations did not follow the home vector, but instead showed random heading directions. Foragers with larger home vectors (≥10   m) oriented towards the fictive nest, indicating a possible increase in cue strength with vector length. When the ants were displaced locally to create a conflict between the home direction indicated by the path integrator and terrestrial landmarks, foragers oriented using landmark information exclusively and ignored any accumulated home vector regardless of vector length. When the visual landmarks at the local displacement site were blocked, foragers were unable to orient to the nest direction and their heading directions were randomly distributed. Myrmecia midas ants typically nest at the base of the tree and some individuals forage on the same tree. Foragers collected on the nest tree during evening twilight were unable to orient towards the nest after small lateral displacements away from the nest. This suggests the possibility of high tree fidelity and an inability to extrapolate landmark compass cues from information collected on the tree and at the nest site to close displacement sites. © 2017. Published by The Company of Biologists Ltd.

Orbitofrontal inactivation impairs reversal of Pavlovian learning by interfering with 'disinhibition' of responding for previously unrewarded cues.

PubMed

Burke, Kathryn A; Takahashi, Yuji K; Correll, Jessica; Brown, P Leon; Schoenbaum, Geoffrey

2009-11-01

Orbitofrontal cortex (OFC) is critical for reversal learning. Reversal deficits are typically demonstrated in complex settings that combine Pavlovian and instrumental learning. Yet recent work has implicated the OFC specifically in behaviors guided by cues and the features of the specific outcomes they predict. To test whether the OFC is important for reversing such Pavlovian associations in the absence of confounding instrumental requirements, we trained rats on a simple Pavlovian task in which two auditory cues were presented, one paired with a food pellet reward and the other presented without reward. After learning, we reversed the cue-outcome associations. For half the rats, OFC was inactivated prior to each reversal session. Inactivation of OFC impaired the ability of the rats to reverse conditioned responding. This deficit reflected the inability of inactivated rats to develop normal responding for the previously unrewarded cue; inactivation of OFC had no impact on the ability of the rats to inhibit responding to the previously rewarded cue. These data show that OFC is critical to reversal of Pavlovian responding, and that the role of OFC in this behavior cannot be explained as a simple deficit in response inhibition. Furthermore, the contrast between the normal inhibition of responding, reported here, and impaired inhibition of responding during Pavlovian over-expectation, reported previously, suggests the novel hypothesis that OFC may be particularly critical for learning (or behavior) when it requires the subject to generate predictions about outcomes by bringing together or integrating disparate pieces of associative information.

Prefrontal cholinergic mechanisms instigating shifts from monitoring for cues to cue-guided performance: Converging electrochemical and fMRI evidence from rats and humans

PubMed Central

Howe, William M.; Berry, Anne S.; Francois, Jennifer; Gilmour, Gary; Carp, Joshua M.; Tricklebank, Mark; Lustig, Cindy; Sarter, Martin

2013-01-01

We previously reported involvement of right prefrontal cholinergic activity in veridical signal detection. Here, we first recorded real-time acetylcholine release in prefrontal cortex during specific trial sequences in rats performing a task requiring signal detection as well as rejection of non-signal events. Cholinergic release events recorded with sub-second resolution (“transients”) were observed only during signal-hit trials, not during signal-miss trials or non-signal events. Moreover, cholinergic transients were not observed for consecutive hits; instead they were limited to signal-hit trials that were preceded by factual or perceived non-signal events (“incongruent hits”). This finding suggests that these transients mediate shifts from a state of perceptual attention, or monitoring for cues, to cue-evoked activation of response rules and the generation of a cue-directed response. Next, to determine the translational significance of the cognitive operations supporting incongruent hits we employed a version of the task previously validated for use in research in humans and BOLD-fMRI. Incongruent hits activated a region in the right rostral prefrontal cortex (BA 10). Furthermore, greater prefrontal activation was correlated with faster response times for incongruent hits. Finally, we measured tissue oxygen in rats, as a proxy for BOLD, and found prefrontal increases in oxygen levels solely during incongruent hits. These cross-species studies link a cholinergic response to a prefrontal BOLD activation and indicate that these interrelated mechanisms mediate the integration of external cues with internal representations to initiate and guide behavior. PMID:23678117

Large capacity storage of integrated objects before change blindness.

PubMed

Landman, Rogier; Spekreijse, Henk; Lamme, Victor A F

2003-01-01

Normal people have a strikingly low ability to detect changes in a visual scene. This has been taken as evidence that the brain represents only a few objects at a time, namely those currently in the focus of attention. In the present study, subjects were asked to detect changes in the orientation of rectangular figures in a textured display across a 1600 ms gray interval. In the first experiment, change detection improved when the location of a possible change was cued during the interval. The cue remained effective during the entire interval, but after the interval, it was ineffective, suggesting that an initially large representation was overwritten by the post-change display. To control for an effect of light intensity during the interval on the decay of the representation, we compared performance with a gray or a white interval screen in a second experiment. We found no difference between these conditions. In the third experiment, attention was occasionally misdirected during the interval by first cueing the wrong figure, before cueing the correct figure. This did not compromise performance compared to a single cue, indicating that when an item is attentionally selected, the representation of yet unchosen items remains available. In the fourth experiment, the cue was shown to be effective when changes in figure size and orientation were randomly mixed. At the time the cue appeared, subjects could not know whether size or orientation would change, therefore these results suggest that the representation contains features in their 'bound' state. Together, these findings indicate that change blindness involves overwriting of a large capacity representation by the post-change display.

Simple gaze-contingent cues guide eye movements in a realistic driving simulator

NASA Astrophysics Data System (ADS)

Pomarjanschi, Laura; Dorr, Michael; Bex, Peter J.; Barth, Erhardt

2013-03-01

Looking at the right place at the right time is a critical component of driving skill. Therefore, gaze guidance has the potential to become a valuable driving assistance system. In previous work, we have already shown that complex gaze-contingent stimuli can guide attention and reduce the number of accidents in a simple driving simulator. We here set out to investigate whether cues that are simple enough to be implemented in a real car can also capture gaze during a more realistic driving task in a high-fidelity driving simulator. We used a state-of-the-art, wide-field-of-view driving simulator with an integrated eye tracker. Gaze-contingent warnings were implemented using two arrays of light-emitting diodes horizontally fitted below and above the simulated windshield. Thirteen volunteering subjects drove along predetermined routes in a simulated environment popu­ lated with autonomous traffic. Warnings were triggered during the approach to half of the intersections, cueing either towards the right or to the left. The remaining intersections were not cued, and served as controls. The analysis of the recorded gaze data revealed that the gaze-contingent cues did indeed have a gaze guiding effect, triggering a significant shift in gaze position towards the highlighted direction. This gaze shift was not accompanied by changes in driving behaviour, suggesting that the cues do not interfere with the driving task itself.

Pictures cueing threat: brain dynamics in viewing explicitly instructed danger cues

PubMed Central

Schupp, Harald T.

2012-01-01

Recent event-related brain potential studies revealed the selective processing of emotional and threatening pictures. Integrating the picture viewing and threat-of-shock paradigm, the present study examined the processing of emotional pictures while they were explicitly instructed to cue threat of real world danger (i.e. electric shocks). Toward this end, 60 pleasant, neutral and unpleasant IAPS-pictures were presented (1 s) as a continuous random stream while high-density EEG and self-reported threat were assessed. In three experimental runs, each picture category was used once as a threat-cue, whereas in the other conditions the same category served as safety-cue. An additional passive viewing run served as a no-threat condition, thus, establishing a threat–safety continuum (threat-cue–safety-cue–no-threat) for each picture category. Threat-of-shock modulated P1, P2 and parieto-occipital LPP amplitudes. While the P1 component differentiated among threat- and no-threat conditions, the P2 and LPP effects were specific to pictures signaling threat-of-shock. Thus, stimulus processing progressively gained more accurate information about environmental threat conditions. Interestingly, the finding of increased EPN and centro-parietal LPP amplitudes to emotional pictures was independent from threat-of-shock manipulation. Accordingly, the results indicate distinct effects associated with the intrinsic significance of emotional pictures and explicitly instructed threat contingencies. PMID:21719425

Developmental changes in sensitivity to vocal paralanguage

PubMed Central

Friend, Margaret

2017-01-01

Developmental changes in children’s sensitivity to the role of acoustic variation in the speech stream in conveying speaker affect (vocal paralanguage) were examined. Four-, 7- and 10-year-olds heard utterances in three formats: low-pass filtered, reiterant, and normal speech. The availability of lexical and paralinguistic information varied across these three formats in a way that required children to base their judgments of speaker affect on different configurations of cues in each format. Across ages, the best performance was obtained when a rich array of acoustic cues was present and when there was no competing lexical information. Four-year-olds performed at chance when judgments had to be based solely on speech prosody in the filtered format and they were unable to selectively attend to paralanguage when discrepant lexical cues were present in normal speech. Seven-year-olds were significantly more sensitive to the paralinguistic role of speech prosody in filtered speech than were 4-year-olds and there was a trend toward greater attention to paralanguage when lexical and paralinguistic cues were inconsistent in normal speech. An integration of the ability to utilize prosodic cues to speaker affect with attention to paralanguage in cases of lexical/paralinguistic discrepancy was observed for 10-year-olds. The results are discussed in terms of the development of a perceptual bias emerging out of selective attention to language. PMID:28713218

The effect of feature-based attention on flanker interference processing: An fMRI-constrained source analysis.

PubMed

Siemann, Julia; Herrmann, Manfred; Galashan, Daniela

2018-01-25

The present study examined whether feature-based cueing affects early or late stages of flanker conflict processing using EEG and fMRI. Feature cues either directed participants' attention to the upcoming colour of the target or were neutral. Validity-specific modulations during interference processing were investigated using the N200 event-related potential (ERP) component and BOLD signal differences. Additionally, both data sets were integrated using an fMRI-constrained source analysis. Finally, the results were compared with a previous study in which spatial instead of feature-based cueing was applied to an otherwise identical flanker task. Feature-based and spatial attention recruited a common fronto-parietal network during conflict processing. Irrespective of attention type (feature-based; spatial), this network responded to focussed attention (valid cueing) as well as context updating (invalid cueing), hinting at domain-general mechanisms. However, spatially and non-spatially directed attention also demonstrated domain-specific activation patterns for conflict processing that were observable in distinct EEG and fMRI data patterns as well as in the respective source analyses. Conflict-specific activity in visual brain regions was comparable between both attention types. We assume that the distinction between spatially and non-spatially directed attention types primarily applies to temporal differences (domain-specific dynamics) between signals originating in the same brain regions (domain-general localization).

Looking at the world with your ears: how do we get the size of an object from its sound?

PubMed

Grassi, Massimo; Pastore, Massimiliano; Lemaitre, Guillaume

2013-05-01

Identifying the properties of on-going events by the sound they produce is crucial for our interaction with the environment when visual information is not available. Here, we investigated the ability of listeners to estimate the size of an object (a ball) dropped on a plate with ecological listening conditions (balls were dropped in real time) and response methods (listeners estimate ball-size by drawing a disk). Previous studies had shown that listeners can veridically estimate the size of objects by the sound they produce, but it is yet unclear which acoustical index listeners use to produce their estimates. In particular, it is unclear whether listeners listen to amplitude (related to loudness) or frequency (related to the sound's brightness) domain cue to produce their estimates. In the current study, in order to understand which cue is used by the listener to recover the size of the object, we manipulated the sound source event in such a way that frequency and amplitude cues provided contrasting size-information (balls were dropped from various heights). Results showed that listeners' estimations were accurate regardless of the experimental manipulations performed in the experiments. In addition, results suggest that listeners were likely integrating frequency and amplitude acoustical cues in order to produce their estimate and although these cues were often providing contrasting size-information. Copyright © 2013 Elsevier B.V. All rights reserved.

The role of visuohaptic experience in visually perceived depth.

PubMed

Ho, Yun-Xian; Serwe, Sascha; Trommershäuser, Julia; Maloney, Laurence T; Landy, Michael S

2009-06-01

Berkeley suggested that "touch educates vision," that is, haptic input may be used to calibrate visual cues to improve visual estimation of properties of the world. Here, we test whether haptic input may be used to "miseducate" vision, causing observers to rely more heavily on misleading visual cues. Human subjects compared the depth of two cylindrical bumps illuminated by light sources located at different positions relative to the surface. As in previous work using judgments of surface roughness, we find that observers judge bumps to have greater depth when the light source is located eccentric to the surface normal (i.e., when shadows are more salient). Following several sessions of visual judgments of depth, subjects then underwent visuohaptic training in which haptic feedback was artificially correlated with the "pseudocue" of shadow size and artificially decorrelated with disparity and texture. Although there were large individual differences, almost all observers demonstrated integration of haptic cues during visuohaptic training. For some observers, subsequent visual judgments of bump depth were unaffected by the training. However, for 5 of 12 observers, training significantly increased the weight given to pseudocues, causing subsequent visual estimates of shape to be less veridical. We conclude that haptic information can be used to reweight visual cues, putting more weight on misleading pseudocues, even when more trustworthy visual cues are available in the scene.

Amblypygids: Model Organisms for the Study of Arthropod Navigation Mechanisms in Complex Environments?

PubMed Central

Wiegmann, Daniel D.; Hebets, Eileen A.; Gronenberg, Wulfila; Graving, Jacob M.; Bingman, Verner P.

2016-01-01

Navigation is an ideal behavioral model for the study of sensory system integration and the neural substrates associated with complex behavior. For this broader purpose, however, it may be profitable to develop new model systems that are both tractable and sufficiently complex to ensure that information derived from a single sensory modality and path integration are inadequate to locate a goal. Here, we discuss some recent discoveries related to navigation by amblypygids, nocturnal arachnids that inhabit the tropics and sub-tropics. Nocturnal displacement experiments under the cover of a tropical rainforest reveal that these animals possess navigational abilities that are reminiscent, albeit on a smaller spatial scale, of true-navigating vertebrates. Specialized legs, called antenniform legs, which possess hundreds of olfactory and tactile sensory hairs, and vision appear to be involved. These animals also have enormous mushroom bodies, higher-order brain regions that, in insects, integrate contextual cues and may be involved in spatial memory. In amblypygids, the complexity of a nocturnal rainforest may impose navigational challenges that favor the integration of information derived from multimodal cues. Moreover, the movement of these animals is easily studied in the laboratory and putative neural integration sites of sensory information can be manipulated. Thus, amblypygids could serve as model organisms for the discovery of neural substrates associated with a unique and potentially sophisticated navigational capability. The diversity of habitats in which amblypygids are found also offers an opportunity for comparative studies of sensory integration and ecological selection pressures on navigation mechanisms. PMID:27014008

Space, color, and direction of movement: how do they affect attention?

PubMed

Verghese, Ashika; Anderson, Andrew J; Vidyasagar, Trichur R

2013-07-19

Paying attention improves performance, but is this improvement regardless of what we attend to? We explored the differences in performance between attending to a location and attending to a feature when perceiving global motion. Attention was first cued to one of four locations that had coherently moving dots, while the remaining three had randomly moving distracter dots. Participants then viewed a colored display, wherein the color of the coherently moving dots was cued instead of location. In the third task, participants identified the location that had a particular cued direction of motion. Most observers reported reductions of motion threshold in all three tasks compared to when no cue was provided. However, the attentional bias generated by location cues was significantly larger than the bias resulting from feature cues of direction or color. This effect is consistent with the idea that attention is largely controlled by a fronto-parietal network where spatial relations are preferentially processed. On the other hand, color could not be used as a cue to focus attention and integrate motion. This finding suggests that color relies heavily on processing by ventral temporal cortical areas, which may have little control over the global motion areas in the dorsal part of the brain.

Spatial attention can be biased towards an expected dimension.

PubMed

Burnett, Katherine E; Close, Alex C; d'Avossa, Giovanni; Sapir, Ayelet

2016-11-01

A commonly held view in both exogenous and endogenous orienting is that spatial attention is associated with enhanced processing of all stimuli at the attended location. However, we often search for a specific target at a particular location, so an observer should be able to jointly specify the target identity and expected location. Whether attention can bias dimension-specific processes at a particular location is not yet clear. We used a dual task to examine the effects of endogenous spatial cues on the accuracy of perceptual judgments of different dimensions. Participants responded to a motion target and a colour target, presented at the same or different locations. We manipulated a central cue to predict the location of the motion or colour target. While overall performance in the two tasks was comparable, cueing effects were larger for the target whose location was predicted by the cue, implying that when attending a particular location, processing of the likely dimension was preferentially enhanced. Additionally, an asymmetry between the motion and colour tasks was seen; motion was modulated by attention, and colour was not. We conclude that attention has some ability to select a dimension at a particular location, indicating integration of spatial and feature-based attention.

Steering intermediate courses: desert ants combine information from various navigational routines.

PubMed

Wehner, Rüdiger; Hoinville, Thierry; Cruse, Holk; Cheng, Ken

2016-07-01

A number of systems of navigation have been studied in some detail in insects. These include path integration, a system that keeps track of the straight-line distance and direction travelled on the current trip, the use of panoramic landmarks and scenery for orientation, and systematic searching. A traditional view is that only one navigational system is in operation at any one time, with different systems running in sequence depending on the context and conditions. We review selected data suggesting that often, different navigational cues (e.g., compass cues) and different systems of navigation are in operation simultaneously in desert ant navigation. The evidence suggests that all systems operate in parallel forming a heterarchical network. External and internal conditions determine the weights to be accorded to each cue and system. We also show that a model of independent modules feeding into a central summating device, the Navinet model, can in principle account for such data. No central executive processor is necessary aside from a weighted summation of the different cues and systems. Such a heterarchy of parallel systems all in operation represents a new view of insect navigation that has already been expressed informally by some authors.

I want to help you, but I am not sure why: gaze-cuing induces altruistic giving.

PubMed

Rogers, Robert D; Bayliss, Andrew P; Szepietowska, Anna; Dale, Laura; Reeder, Lydia; Pizzamiglio, Gloria; Czarna, Karolina; Wakeley, Judi; Cowen, Phillip J; Tipper, Steven P

2014-04-01

Detecting subtle indicators of trustworthiness is highly adaptive for moving effectively amongst social partners. One powerful signal is gaze direction, which individuals can use to inform (or deceive) by looking toward (or away from) important objects or events in the environment. Here, across 5 experiments, we investigate whether implicit learning about gaze cues can influence subsequent economic transactions; we also examine some of the underlying mechanisms. In the 1st experiment, we demonstrate that people invest more money with individuals whose gaze information has previously been helpful, possibly reflecting enhanced trust appraisals. However, in 2 further experiments, we show that other mechanisms driving this behavior include obligations to fairness or (painful) altruism, since people also make more generous offers and allocations of money to individuals with reliable gaze cues in adapted 1-shot ultimatum games and 1-shot dictator games. In 2 final experiments, we show that the introduction of perceptual noise while following gaze can disrupt these effects, but only when the social partners are unfamiliar. Nonconscious detection of reliable gaze cues can prompt altruism toward others, probably reflecting the interplay of systems that encode identity and control gaze-evoked attention, integrating the reinforcement value of gaze cues.

Biochemical and Biophysical Cues in Matrix Design for Chronic and Diabetic Wound Treatment

PubMed Central

Xiao, Yun; Ahadian, Samad

2017-01-01

Progress in biomaterial science and engineering and increasing knowledge in cell biology have enabled us to develop functional biomaterials providing appropriate biochemical and biophysical cues for tissue regeneration applications. Tissue regeneration is particularly important to treat chronic wounds of people with diabetes. Understanding and controlling the cellular microenvironment of the wound tissue are important to improve the wound healing process. In this study, we review different biochemical (e.g., growth factors, peptides, DNA, and RNA) and biophysical (e.g., topographical guidance, pressure, electrical stimulation, and pulsed electromagnetic field) cues providing a functional and instructive acellular matrix to heal diabetic chronic wounds. The biochemical and biophysical signals generally regulate cell–matrix interactions and cell behavior and function inducing the tissue regeneration for chronic wounds. Some technologies and devices have already been developed and used in the clinic employing biochemical and biophysical cues for wound healing applications. These technologies can be integrated with smart biomaterials to deliver therapeutic agents to the wound tissue in a precise and controllable manner. This review provides useful guidance in understanding molecular mechanisms and signals in the healing of diabetic chronic wounds and in designing instructive biomaterials to treat them. PMID:27405960

Facilitation effect of observed motor deviants in a cooperative motor task: Evidence for direct perception of social intention in action.

PubMed

Quesque, François; Delevoye-Turrell, Yvonne; Coello, Yann

2016-01-01

Spatiotemporal parameters of voluntary motor action may help optimize human social interactions. Yet it is unknown whether individuals performing a cooperative task spontaneously perceive subtly informative social cues emerging through voluntary actions. In the present study, an auditory cue was provided through headphones to an actor and a partner who faced each other. Depending on the pitch of the auditory cue, either the actor or the partner were required to grasp and move a wooden dowel under time constraints from a central to a lateral position. Before this main action, the actor performed a preparatory action under no time constraint, consisting in placing the wooden dowel on the central location when receiving either a neutral ("prêt"-ready) or an informative auditory cue relative to who will be asked to perform the main action (the actor: "moi"-me, or the partner: "lui"-him). Although the task focused on the main action, analysis of motor performances revealed that actors performed the preparatory action with longer reaction times and higher trajectories when informed that the partner would be performing the main action. In this same condition, partners executed the main actions with shorter reaction times and lower velocities, despite having received no previous informative cues. These results demonstrate that the mere observation of socially driven motor actions spontaneously influences the low-level kinematics of voluntary motor actions performed by the observer during a cooperative motor task. These findings indicate that social intention can be anticipated from the mere observation of action patterns.

Innate Host Habitat Preference in the Parasitoid Diachasmimorpha longicaudata: Functional Significance and Modifications through Learning.

PubMed

Segura, Diego F; Nussenbaum, Ana L; Viscarret, Mariana M; Devescovi, Francisco; Bachmann, Guillermo E; Corley, Juan C; Ovruski, Sergio M; Cladera, Jorge L

2016-01-01

Parasitoids searching for polyphagous herbivores can find their hosts in a variety of habitats. Under this scenario, chemical cues from the host habitat (not related to the host) represent poor indicators of host location. Hence, it is unlikely that naïve females show a strong response to host habitat cues, which would become important only if the parasitoids learn to associate such cues to the host presence. This concept does not consider that habitats can vary in profitability or host nutritional quality, which according to the optimal foraging theory and the preference-performance hypothesis (respectively) could shape the way in which parasitoids make use of chemical cues from the host habitat. We assessed innate preference in the fruit fly parasitoid Diachasmimorpha longicaudata among chemical cues from four host habitats (apple, fig, orange and peach) using a Y-tube olfactometer. Contrary to what was predicted, we found a hierarchic pattern of preference. The parasitism rate realized on these fruit species and the weight of the host correlates positively, to some extent, with the preference pattern, whereas preference did not correlate with survival and fecundity of the progeny. As expected for a parasitoid foraging for generalist hosts, habitat preference changed markedly depending on their previous experience and the abundance of hosts. These findings suggest that the pattern of preference for host habitats is attributable to differences in encounter rate and host quality. Host habitat preference seems to be, however, quite plastic and easily modified according to the information obtained during foraging.

Innate Host Habitat Preference in the Parasitoid Diachasmimorpha longicaudata: Functional Significance and Modifications through Learning

PubMed Central

Segura, Diego F.; Nussenbaum, Ana L.; Viscarret, Mariana M.; Devescovi, Francisco; Bachmann, Guillermo E.; Corley, Juan C.; Ovruski, Sergio M.; Cladera, Jorge L.

2016-01-01

Parasitoids searching for polyphagous herbivores can find their hosts in a variety of habitats. Under this scenario, chemical cues from the host habitat (not related to the host) represent poor indicators of host location. Hence, it is unlikely that naïve females show a strong response to host habitat cues, which would become important only if the parasitoids learn to associate such cues to the host presence. This concept does not consider that habitats can vary in profitability or host nutritional quality, which according to the optimal foraging theory and the preference-performance hypothesis (respectively) could shape the way in which parasitoids make use of chemical cues from the host habitat. We assessed innate preference in the fruit fly parasitoid Diachasmimorpha longicaudata among chemical cues from four host habitats (apple, fig, orange and peach) using a Y-tube olfactometer. Contrary to what was predicted, we found a hierarchic pattern of preference. The parasitism rate realized on these fruit species and the weight of the host correlates positively, to some extent, with the preference pattern, whereas preference did not correlate with survival and fecundity of the progeny. As expected for a parasitoid foraging for generalist hosts, habitat preference changed markedly depending on their previous experience and the abundance of hosts. These findings suggest that the pattern of preference for host habitats is attributable to differences in encounter rate and host quality. Host habitat preference seems to be, however, quite plastic and easily modified according to the information obtained during foraging. PMID:27007298

Toward the establishment of design guidelines for effective 3D perspective interfaces

NASA Astrophysics Data System (ADS)

Fitzhugh, Elisabeth; Dixon, Sharon; Aleva, Denise; Smith, Eric; Ghrayeb, Joseph; Douglas, Lisa

2009-05-01

The propagation of information operation technologies, with correspondingly vast amounts of complex network information to be conveyed, significantly impacts operator workload. Information management research is rife with efforts to develop schemes to aid operators to identify, review, organize, and retrieve the wealth of available data. Data may take on such distinct forms as intelligence libraries, logistics databases, operational environment models, or network topologies. Increased use of taxonomies and semantic technologies opens opportunities to employ network visualization as a display mechanism for diverse information aggregations. The broad applicability of network visualizations is still being tested, but in current usage, the complexity of densely populated abstract networks suggests the potential utility of 3D. Employment of 2.5D in network visualization, using classic perceptual cues, creates a 3D experience within a 2D medium. It is anticipated that use of 3D perspective (2.5D) will enhance user ability to visually inspect large, complex, multidimensional networks. Current research for 2.5D visualizations demonstrates that display attributes, including color, shape, size, lighting, atmospheric effects, and shadows, significantly impact operator experience. However, guidelines for utilization of attributes in display design are limited. This paper discusses pilot experimentation intended to identify potential problem areas arising from these cues and determine how best to optimize perceptual cue settings. Development of optimized design guidelines will ensure that future experiments, comparing network displays with other visualizations, are not confounded or impeded by suboptimal attribute characterization. Current experimentation is anticipated to support development of cost-effective, visually effective methods to implement 3D in military applications.

Effects of Motion Cues on the Training of Multi-Axis Manual Control Skills

NASA Technical Reports Server (NTRS)

Zaal, Peter M. T.; Mobertz, Xander R. I.

2017-01-01

The study described in this paper investigated the effects of two different hexapod motion configurations on the training and transfer of training of a simultaneous roll and pitch control task. Pilots were divided between two groups which trained either under a baseline hexapod motion condition, with motion typically provided by current training simulators, or an optimized hexapod motion condition, with increased fidelity of the motion cues most relevant for the task. All pilots transferred to the same full-motion condition, representing motion experienced in flight. A cybernetic approach was used that gave insights into the development of pilots use of visual and motion cues over the course of training and after transfer. Based on the current results, neither of the hexapod motion conditions can unambiguously be chosen as providing the best motion for training and transfer of training of the used multi-axis control task. However, the optimized hexapod motion condition did allow pilots to generate less visual lead, control with higher gains, and have better disturbance-rejection performance at the end of the training session compared to the baseline hexapod motion condition. Significant adaptations in control behavior still occurred in the transfer phase under the full-motion condition for both groups. Pilots behaved less linearly compared to previous single-axis control-task experiments; however, this did not result in smaller motion or learning effects. Motion and learning effects were more pronounced in pitch compared to roll. Finally, valuable lessons were learned that allow us to improve the adopted approach for future transfer-of-training studies.

Individual differences in voluntary alcohol intake in rats: relationship with impulsivity, decision making and Pavlovian conditioned approach.

PubMed

Spoelder, Marcia; Flores Dourojeanni, Jacques P; de Git, Kathy C G; Baars, Annemarie M; Lesscher, Heidi M B; Vanderschuren, Louk J M J

2017-07-01

Alcohol use disorder (AUD) has been associated with suboptimal decision making, exaggerated impulsivity, and aberrant responses to reward-paired cues, but the relationship between AUD and these behaviors is incompletely understood. This study aims to assess decision making, impulsivity, and Pavlovian-conditioned approach in rats that voluntarily consume low (LD) or high (HD) amounts of alcohol. LD and HD were tested in the rat gambling task (rGT) or the delayed reward task (DRT). Next, the effect of alcohol (0-1.0 g/kg) was tested in these tasks. Pavlovian-conditioned approach (PCA) was assessed both prior to and after intermittent alcohol access (IAA). Principal component analyses were performed to identify relationships between the most important behavioral parameters. HD showed more optimal decision making in the rGT. In the DRT, HD transiently showed reduced impulsive choice. In both LD and HD, alcohol treatment increased optimal decision making in the rGT and increased impulsive choice in the DRT. PCA prior to and after IAA was comparable for LD and HD. When PCA was tested after IAA only, HD showed a more sign-tracking behavior. The principal component analyses indicated dimensional relationships between alcohol intake, impulsivity, and sign-tracking behavior in the PCA task after IAA. HD showed a more efficient performance in the rGT and DRT. Moreover, alcohol consumption enhanced approach behavior to reward-predictive cues, but sign-tracking did not predict the level of alcohol consumption. Taken together, these findings suggest that high levels of voluntary alcohol intake are associated with enhanced cue- and reward-driven behavior.

Optimal combination of illusory and luminance-defined 3-D surfaces: A role for ambiguity.

PubMed

Hartle, Brittney; Wilcox, Laurie M; Murray, Richard F

2018-04-01

The shape of the illusory surface in stereoscopic Kanizsa figures is determined by the interpolation of depth from the luminance edges of adjacent inducing elements. Despite ambiguity in the position of illusory boundaries, observers reliably perceive a coherent three-dimensional (3-D) surface. However, this ambiguity may contribute additional uncertainty to the depth percept beyond what is expected from measurement noise alone. We evaluated the intrinsic ambiguity of illusory boundaries by using a cue-combination paradigm to measure the reliability of depth percepts elicited by stereoscopic illusory surfaces. We assessed the accuracy and precision of depth percepts using 3-D Kanizsa figures relative to luminance-defined surfaces. The location of the surface peak was defined by illusory boundaries, luminance-defined edges, or both. Accuracy and precision were assessed using a depth-discrimination paradigm. A maximum likelihood linear cue combination model was used to evaluate the relative contribution of illusory and luminance-defined signals to the perceived depth of the combined surface. Our analysis showed that the standard deviation of depth estimates was consistent with an optimal cue combination model, but the points of subjective equality indicated that observers consistently underweighted the contribution of illusory boundaries. This systematic underweighting may reflect a combination rule that attributes additional intrinsic ambiguity to the location of the illusory boundary. Although previous studies show that illusory and luminance-defined contours share many perceptual similarities, our model suggests that ambiguity plays a larger role in the perceptual representation of illusory contours than of luminance-defined contours.

Motivational State, Reward Value, and Pavlovian Cues Differentially Affect Skilled Forelimb Grasping in Rats

ERIC Educational Resources Information Center

Mosberger, Alice C.; de Clauser, Larissa; Kasper, Hansjörg; Schwab, Martin E.

2016-01-01

Motor skills represent high-precision movements performed at optimal speed and accuracy. Such motor skills are learned with practice over time. Besides practice, effects of motivation have also been shown to influence speed and accuracy of movements, suggesting that fast movements are performed to maximize gained reward over time as noted in…

Use of Linear Perspective Scene Cues in a Simulated Height Regulation Task

NASA Technical Reports Server (NTRS)

Levison, W. H.; Warren, R.

1984-01-01

As part of a long-term effort to quantify the effects of visual scene cuing and non-visual motion cuing in flight simulators, an experimental study of the pilot's use of linear perspective cues in a simulated height-regulation task was conducted. Six test subjects performed a fixed-base tracking task with a visual display consisting of a simulated horizon and a perspective view of a straight, infinitely-long roadway of constant width. Experimental parameters were (1) the central angle formed by the roadway perspective and (2) the display gain. The subject controlled only the pitch/height axis; airspeed, bank angle, and lateral track were fixed in the simulation. The average RMS height error score for the least effective display configuration was about 25% greater than the score for the most effective configuration. Overall, larger and more highly significant effects were observed for the pitch and control scores. Model analysis was performed with the optimal control pilot model to characterize the pilot's use of visual scene cues, with the goal of obtaining a consistent set of independent model parameters to account for display effects.

How chimpanzees integrate sensory information to select figs

PubMed Central

Yeakel, Justin D.; Bhat, Uttam; Ramsden, Lawrence; Wrangham, Richard W.; Lucas, Peter W.

2016-01-01

Figs are keystone resources that sustain chimpanzees when preferred fruits are scarce. Many figs retain a green(ish) colour throughout development, a pattern that causes chimpanzees to evaluate edibility on the basis of achromatic accessory cues. Such behaviour is conspicuous because it entails a succession of discrete sensory assessments, including the deliberate palpation of individual figs, a task that requires advanced visuomotor control. These actions are strongly suggestive of domain-specific information processing and decision-making, and they call attention to a potential selective force on the origin of advanced manual prehension and digital dexterity during primate evolution. To explore this concept, we report on the foraging behaviours of chimpanzees and the spectral, chemical and mechanical properties of figs, with cutting tests revealing ease of fracture in the mouth. By integrating the ability of different sensory cues to predict fructose content in a Bayesian updating framework, we quantified the amount of information gained when a chimpanzee successively observes, palpates and bites the green figs of Ficus sansibarica. We found that the cue eliciting ingestion was not colour or size, but fig mechanics (including toughness estimates from wedge tests), which relays higher-quality information on fructose concentrations than colour vision. This result explains why chimpanzees evaluate green figs by palpation and dental incision, actions that could explain the adaptive origins of advanced manual prehension. PMID:27274803

Does the Integration of Haptic and Visual Cues Reduce the Effect of a Biased Visual Reference Frame on the Subjective Head Orientation?

PubMed Central

Gueguen, Marc; Vuillerme, Nicolas; Isableu, Brice

2012-01-01

Background The selection of appropriate frames of reference (FOR) is a key factor in the elaboration of spatial perception and the production of robust interaction with our environment. The extent to which we perceive the head axis orientation (subjective head orientation, SHO) with both accuracy and precision likely contributes to the efficiency of these spatial interactions. A first goal of this study was to investigate the relative contribution of both the visual and egocentric FOR (centre-of-mass) in the SHO processing. A second goal was to investigate humans' ability to process SHO in various sensory response modalities (visual, haptic and visuo-haptic), and the way they modify the reliance to either the visual or egocentric FORs. A third goal was to question whether subjects combined visual and haptic cues optimally to increase SHO certainty and to decrease the FORs disruption effect. Methodology/Principal Findings Thirteen subjects were asked to indicate their SHO while the visual and/or egocentric FORs were deviated. Four results emerged from our study. First, visual rod settings to SHO were altered by the tilted visual frame but not by the egocentric FOR alteration, whereas no haptic settings alteration was observed whether due to the egocentric FOR alteration or the tilted visual frame. These results are modulated by individual analysis. Second, visual and egocentric FOR dependency appear to be negatively correlated. Third, the response modality enrichment appears to improve SHO. Fourth, several combination rules of the visuo-haptic cues such as the Maximum Likelihood Estimation (MLE), Winner-Take-All (WTA) or Unweighted Mean (UWM) rule seem to account for SHO improvements. However, the UWM rule seems to best account for the improvement of visuo-haptic estimates, especially in situations with high FOR incongruence. Finally, the data also indicated that FOR reliance resulted from the application of UWM rule. This was observed more particularly, in the visual dependent subject. Conclusions: Taken together, these findings emphasize the importance of identifying individual spatial FOR preferences to assess the efficiency of our interaction with the environment whilst performing spatial tasks. PMID:22509295

Promoting pre-quit physical activity to reduce cue reactivity among low-income sedentary smokers: A randomized proof of concept study.

PubMed

Nair, Uma S; Collins, Bradley N; Patterson, Freda; Rodriguez, Daniel

2015-05-01

Smoking and lack of physical activity (PA) contribute to disproportionate rates of disease among low-income adults. Interventions that simultaneously address both risk behaviors have strong potential to reduce health disparities. Existing smoking-PA studies indicate promising results but have limited generalizability to low-income populations. The goal of this study is to assess the effects of an integrated behavioral counseling approach to promote low-to-moderate intensity PA (LMPA) and reduce short-term smoking cue reactivity among low-income sedentary smokers. This study uses a randomized, 2-group design with 4 measurement time points: baseline, quit day (week 4), 1-week and 1-month follow-up. Participants (sedentary, smoke>6 cigs/day) receive 4 weeks of either (a) standard smoking cessation counseling (SCC control) or (b) our Step-Up to Quit (SUTQ) intervention that integrates advice for LMPA with SCC. SUTQ counseling focuses on increasing daily steps (walking) to reach 7500-10,000/day by week 4 (quit day) and explicitly links short bouts of LMPA with smoking urge management. Potential for SUTQ to facilitate urge management will be assessed by comparing between-group differences in the reduction (extinction) of quit day cue reactivity. We will explore group differences in quit rates at 1-week and 1-month follow-up. This novel approach overcomes gaps in the PA-smoking intervention literature by promoting a more realistic PA approach for sedentary populations, using an ecologically valid strategy, integrating LMPA with evidence-based SCC during a 4-week pre-quit period, and testing the SUTQ counseling model in a high-risk sample. Results will guide future efficacy and dissemination studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Melodic Contour Identification and Music Perception by Cochlear Implant Users

PubMed Central

Galvin, John J.; Fu, Qian-Jie; Shannon, Robert V.

2013-01-01

Research and outcomes with cochlear implants (CIs) have revealed a dichotomy in the cues necessary for speech and music recognition. CI devices typically transmit 16–22 spectral channels, each modulated slowly in time. This coarse representation provides enough information to support speech understanding in quiet and rhythmic perception in music, but not enough to support speech understanding in noise or melody recognition. Melody recognition requires some capacity for complex pitch perception, which in turn depends strongly on access to spectral fine structure cues. Thus, temporal envelope cues are adequate for speech perception under optimal listening conditions, while spectral fine structure cues are needed for music perception. In this paper, we present recent experiments that directly measure CI users’ melodic pitch perception using a melodic contour identification (MCI) task. While normal-hearing (NH) listeners’ performance was consistently high across experiments, MCI performance was highly variable across CI users. CI users’ MCI performance was significantly affected by instrument timbre, as well as by the presence of a competing instrument. In general, CI users had great difficulty extracting melodic pitch from complex stimuli. However, musically-experienced CI users often performed as well as NH listeners, and MCI training in less experienced subjects greatly improved performance. With fixed constraints on spectral resolution, such as it occurs with hearing loss or an auditory prosthesis, training and experience can provide a considerable improvements in music perception and appreciation. PMID:19673835

The perception of emotion and focus prosody with varying acoustic cues in cochlear implant simulations with varying filter slopes

PubMed Central

van de Velde, Daan J.; Schiller, Niels O.; van Heuven, Vincent J.; Levelt, Claartje C.; van Ginkel, Joost; Beers, Mieke; Briaire, Jeroen J.; Frijns, Johan H. M.

2017-01-01

This study aimed to find the optimal filter slope for cochlear implant simulations (vocoding) by testing the effect of a wide range of slopes on the discrimination of emotional and linguistic (focus) prosody, with varying availability of F0 and duration cues. Forty normally hearing participants judged if (non-)vocoded sentences were pronounced with happy or sad emotion, or with adjectival or nominal focus. Sentences were recorded as natural stimuli and manipulated to contain only emotion- or focus-relevant segmental duration or F0 information or both, and then noise-vocoded with 5, 20, 80, 120, and 160 dB/octave filter slopes. Performance increased with steeper slopes, but only up to 120 dB/octave, with bigger effects for emotion than for focus perception. For emotion, results with both cues most closely resembled results with F0, while for focus results with both cues most closely resembled those with duration, showing emotion perception relies primarily on F0, and focus perception on duration. This suggests that filter slopes affect focus perception less than emotion perception because for emotion, F0 is both more informative and more affected. The performance increase until extreme filter slope values suggests that much performance improvement in prosody perception is still to be gained for CI users. PMID:28599540

Steady-state visual evoked potentials as a research tool in social affective neuroscience

PubMed Central

Wieser, Matthias J.; Miskovic, Vladimir; Keil, Andreas

2017-01-01

Like many other primates, humans place a high premium on social information transmission and processing. One important aspect of this information concerns the emotional state of other individuals, conveyed by distinct visual cues such as facial expressions, overt actions, or by cues extracted from the situational context. A rich body of theoretical and empirical work has demonstrated that these socio-emotional cues are processed by the human visual system in a prioritized fashion, in the service of optimizing social behavior. Furthermore, socio-emotional perception is highly dependent on situational contexts and previous experience. Here, we review current issues in this area of research and discuss the utility of the steady-state visual evoked potential (ssVEP) technique for addressing key empirical questions. Methodological advantages and caveats are discussed with particular regard to quantifying time-varying competition among multiple perceptual objects, trial-by-trial analysis of visual cortical activation, functional connectivity, and the control of low-level stimulus features. Studies on facial expression and emotional scene processing are summarized, with an emphasis on viewing faces and other social cues in emotional contexts, or when competing with each other. Further, because the ssVEP technique can be readily accommodated to studying the viewing of complex scenes with multiple elements, it enables researchers to advance theoretical models of socio-emotional perception, based on complex, quasi-naturalistic viewing situations. PMID:27699794

Phrase Lengths and the Perceived Informativeness of Prosodic Cues in Turkish.

PubMed

Dinçtopal Deniz, Nazik; Fodor, Janet Dean

2017-12-01

It is known from previous studies that in many cases (though not all) the prosodic properties of a spoken utterance reflect aspects of its syntactic structure, and also that in many cases (though not all) listeners can benefit from these prosodic cues. A novel contribution to this literature is the Rational Speaker Hypothesis (RSH), proposed by Clifton, Carlson and Frazier. The RSH maintains that listeners are sensitive to possible reasons for why a speaker might introduce a prosodic break: "listeners treat a prosodic boundary as more informative about the syntax when it flanks short constituents than when it flanks longer constituents," because in the latter case the speaker might have been motivated solely by consideration of optimal phrase lengths. This would effectively reduce the cue value of an appropriately placed prosodic boundary. We present additional evidence for the RSH from Turkish, a language typologically different from English. In addition, our study shows for the first time that the RSH also applies to a prosodic break which conflicts with the syntactic structure, reducing its perceived cue strength if it might have been motivated by length considerations. In this case, the RSH effect is beneficial. Finally, the Turkish data show that prosody-based explanations for parsing preferences such as the RSH do not take the place of traditional syntax-sensitive parsing strategies such as Late Closure. The two sources of guidance co-exist; both are used when available.

Kinematic cues in perceptual weight judgement and their origins in box lifting

PubMed Central

Hamilton, A.; Joyce, D. W.; Flanagan, R.; Frith, C. D.; Wolpert, D. M.

2009-01-01

When accepting a parcel from another person, we are able to use information about that person’s movement to estimate in advance the weight of the parcel, that is, to judge its weight from observed action. Perceptual weight judgment provides a powerful method to study our interpretation of other people’s actions, but it is not known what sources of information are used in judging weight. We have manipulated full form videos to obtain precise control of the perceived kinematics of a box lifting action, and use this technique to explore the kinematic cues that affect weight judgment. We find that observers rely most on the duration of the lifting movement to judge weight, and make less use of the durations of the grasp phase, when the box is first gripped, or the place phase, when the box is put down. These findings can be compared to the kinematics of natural box lifting behaviour, where we find that the duration of the grasp component is the best predictor of true box weight. The lack of accord between the optimal cues predicted by the natural behaviour and the cues actually used in the perceptual task has implications for our understanding of action observation in terms of a motor simulation. The differences between perceptual and motor behaviour are evidence against a strong version of the motor simulation hypothesis. PMID:16311765

Mechanical design in embryos: mechanical signalling, robustness and developmental defects.

PubMed

Davidson, Lance A

2017-05-19

Embryos are shaped by the precise application of force against the resistant structures of multicellular tissues. Forces may be generated, guided and resisted by cells, extracellular matrix, interstitial fluids, and how they are organized and bound within the tissue's architecture. In this review, we summarize our current thoughts on the multiple roles of mechanics in direct shaping, mechanical signalling and robustness of development. Genetic programmes of development interact with environmental cues to direct the composition of the early embryo and endow cells with active force production. Biophysical advances now provide experimental tools to measure mechanical resistance and collective forces during morphogenesis and are allowing integration of this field with studies of signalling and patterning during development. We focus this review on concepts that highlight this integration, and how the unique contributions of mechanical cues and gradients might be tested side by side with conventional signalling systems. We conclude with speculation on the integration of large-scale programmes of development, and how mechanical responses may ensure robust development and serve as constraints on programmes of tissue self-assembly.This article is part of the themed issue 'Systems morphodynamics: understanding the development of tissue hardware'. © 2017 The Author(s).